Engine: Seals, Belts, Crankcase Ventilation                                             FAQ Home
Volvo Maintenance FAQ for 7xx/9xx/90 Cars                                                                                                                     Version 5.0
B230 Engines:

Timing Belt, Seals and Tensioner Preventive Maintenance

Changing Timing Belt: Procedures

Changing Timing Belt: Bolt Removal

Timing Belt Tips: Top Dead Center

Timing Belt Tips

Belt Adjustment After Installation

Timing Belt Tensioner

Accessory Belt Tightening and Maintenance

Alternator Belt Change

Alternator Belt Slips and Doesnít Charge

B6300 Engines:

960 Timing Belt Change

960 Serpentine Belt Installation

960 Rear Cam Seal Repair

B234 Engines:

B234 Timing Belt: New Oil Pump Bolt Needed

B234 Seals:  Counterhold Tool


Crankcase Ventilation: A Treatise

Flame Trap & Crankcase Ventilation Questions

Excess Crankcase Pressure

Excess Crankcase Pressure? Dipstick O-Ring Fails

Oil Breather Box Beneath Flame Trap

Finding Engine Oil Leaks

Cleaning Your Engine

Replacing Oil Seals

Leaking Rear Seal and Replacement Tips

Crank Seal Leaks After Installation

Cam Seal Replacement

Damaged Cam Gear While Changing Seal



Timing Belt, Seals and Tensioner Preventive Maintenance in B23/B230 Series. [From RPR: illustration copyright and used by permission]
Four-cylinder engines 1976 and later all drive the camshaft(s) and intermediate shaft with a toothed timing belt. This part is replaced during normal maintenance every 45,000 or 50,000 miles, depending on your year and model. See the owner's manual.  It is highly advisable to change the seals on cam, intermediate and crank shafts when changing the belt at 90,000 miles or more. Additionally, at 135,000 or more miles, consider replacing the timing belt tensioner, since its bearing will not last much longer. Always carefully inspect the crankshaft sprocket for cracks along the keyway that locks it to the crank. If your front seals (or any engine seals) are leaking, or you find your dipstick pushed up after running the engine, check your flame trap!  For 960 B6300 series engines, see 960 Timing Belt Change below.


Changing Timing Belt: Procedures for B23/B230 Series Engines.

1.  For Pre-1994 B23/B230 Engines.  See Michael Ponte's excellent website at http://www.mikeponte.com/volvo/timing.htm, a complete illustrated guide to changing the timing belt in B23/230 engines.  The following is from Michael:

2.  For 1994+ B230FD and FT (incl EGR) Engines.  See the detailed and illustrated procedure at http://owners.volvocars.com  The login ID and password are "VIP" and "VISIONS".  Text is as follows (courtesy of Volvo):

3.  Plate, Pulley and Tensioner Re-Assembly.  [Query:] I got the crank pulley on my 91 740 off finally, retimed the sprockets and the crank is on TDC. I now need to reassemble everything. The first question I have is which guide plate goes in first. There are two: one has a u- shape hole on the edge, and the other has two holes on the edge, a rectangular shape hole, and an additional small notch on the opposite side. Which plate goes in first?
Then the crank gear sprocket goes in one way. Next goes the other guide plate. Which way?   The guide plate with two holes in the edge fits tight on the crank gear, but the plate with only one hole does not fit tight in any possible  configuration, and just site there wiggling around. So where does it go?   Another reason for question is because when I go to put the timing belt on the crank gear, what is going to hold the gear still. Certainly the one plate will be wobbling if it is on the outside.   [Response: Don Foster] You'll notice that the "guide plates", as you call them, are flared or beveled or dished or bell-shaped -- pick your descriptive term. They must be oriented so the flare is away from the belt. Otherwise the sharp edge will quickly abrade the belt.
First, slide one "plate" over the crank. I think the plate with a notch fits over the woodruff key. Be sure  the "dish" is toward the engine.  Then fit the crank sprocket, again over the key.  Then install the timing belt, taking all the previously-mentioned precautions to align timing marks on belt, sprockets, and block.  Release the tensioner to hold the belt against the sprockets.
Install the outer "guide plate", nearest you (this one dies not need to fit over the key), assuring the "dish" is outward (toward you) so it won't cut the belt. It has no orientation, other than dished-out. (And the inner plate has a keyway simply so it'll fit over the key -- it doesn't otherwise need to be "timed".)  Install the lower cover.
Install the front crank pulley (vibration damper). Because the top belt cover is still off, you can insert the crank tool over the tensioner stud to hold the pulley while you tighten and torque the center bolt. NOTE:  It is this that holds the inner parts tightly in place. The front pulley bears against the timing sprocket and two "plates", squeezing them against the crankshaft. It's a big sandwich.

4.  Tips and Ideas.  See the sections below on Bolt Removal, establishing Top Dead Center, various Timing Belt Installation Tips, and Adjusting the Belt After Installation.


Changing Timing Belt: Bolt Removal in B23/B230.
[Size Comment from Don Foster]  A 24 mm socket fits the crankshaft pulley bolt on my '86 245 and my '91 740 (both B230 engines). A 1/2" drive Craftsman socket would probably be perfect.  On the B230, don't forget that an impact wrench is NOT a good idea because of the risk of snapping the crank. You'll need some way of holding the crank or pulley so you can use a breaker bar.

[Added Notes] I would like to add my experience with the crankshaft bolt on the automatictransmission B230F. When the time came to replace my timing belt the first time, I tried every manner of removal for my crankshaft bolt. Nothing would budge that thing. Out of desperation, I sent off for the special tool 5284 which turned out to be a godsend. In order to break the bolt free, I had to literally jump and down on my 15 inch long wrench (I weigh 180 lbs.) multiple times. I bought the car new, so it came from the factory way over torqued. Despite the upfront cost, the tool was a worthwhile purchase and I would recommend it for anyone contemplating keeping their brick for a long time. At the time, it cost me $45 US from an out of state dealer who discounts 20% for out of state purchases. The tool for holding the B230 crankshaft pulley to loosen/tighten the center bolt is called "Counterhold: for vibration damper"  Part # 999 5284-8

[Another technique:] Had same difficulty when changing belts on both 745 & 245, after much aggravation, bought a large (12", I believe, made by RIGID) plumbers' strap wrench at professional plumbers supply. This enabled me to hold pulley without damaging it so that I could remove it to change belt. [But: SEE BELOW for a Warning.] For really tight ones, it helps to have a cooperative assistant to hold strap wrench. [Another technique for tightening:] For the camshaft and intermediate shaft pulleys, what I did was wrap the old timing belt around the pulley as padding, grip the padded wheel with my largest channel-lock pliers, (a big pipe wrench would also do) and torque the bolt to 37 ft/lbs. [Another technique but SEE BELOW for a Warning:] here's a great way of loosening the crank bolt regardless if you have a stick or auto. All you need is a socket wrench and some blocks. Put the socket over the crank bolt and support the wrench with some blocks/bricks (on the driver's side of the crank). The blocks go under the head and handle of the wrench so that it (wrench) sits parallel to the ground. Disconnect your coil wire and give the starter a turn (about half a second). As the engine cranks over, the bolt will loosen itself against the wrench which is stationary against the blocks. I've done this about five times now and never fails. The harder part is actually removing the pulley!

[Two Caveats on Bolt Removal:] [Tip from Tom Irwin:] Here one problem to watch out for... B230 lower timing pulleys have a little 'nib' extrusion that does the work of a keyway/shaft. It is a cast part and it is delicate.  In the old days we used to fix a large socket and breaker bar over the pulley bolt, wedge it against something solid and whap the starter over to break loose the bolt... DON'T DO IT!  That little key/nib will break off or weaken so it breaks later and ALL your accessory drives (alt/ps/ac/etc) stops spinning.  Oh yah! that little chunk o'metal is special order and about a hundred bucks!   Get the right tool (Volvo 5284) and restrain the pulley

[Another Caveat Tip:]    While the "strap around the crank pulley" method will work just fine on the 84 B23, I'd be very careful doing this to the 88 B230. The 84 B23 has a solid metal crank pulley that should have no problems with this method but, all B230's (that's 85 and newer) use a two piece crank pulley. Not two piece like the B23's pulley, two piece like a common harmonic balancer. In fact that's what it is, a center pulley section with a rubber strip sandwiched between it and an outer pulley section. The early B230's had some problems with the outer pulley section "moving" because the rubber was not holding it tight enough. This causes no problems until you try to set the timing etc. Remember where the timing mark is? That's right, on the outer section of the crank pulley, (harmonic balancer). Holding the outer section of B230 crank pulley to loosen/tighten the center bolt would tend to promote movement of the outer pulley section. The early B230's moved on their own without help, think of the movement possibilities with help! That being said, I wouldn't recommend holding the outer section of a B230 crank pulley to either loosen or tighten the center pulley bolt. If you plan on keeping your car and will be changing the timing belt yourself, buy a tool from Volvo they're not that much. As a heads up to everyone, if you find the timing mark "way off" when checking the ignition timing of a B230 (it usually way retarded). Make sure the pulley is OK first, before doing anything drastic. OK, OK you're right, buying a new B230 crank pulley is pretty drastic too, they don't come cheap. I've changed more than a couple pulleys, not only because you can't check the timing properly. It's because once the outer pulley section has moved you can be certain it's loose. Once it's loose, how long before it flies off completely! Will it happen at 70 MPH in traffic! Thankfully I've only seen this happen once or twice and no major damage was done but you do loose all the belts etc. and a tow truck is in your future.

[Another technique:] The inexpensive alternative (actually free using standard tools): After jacking up the car, remove the flywheel inspection plate (4 bolts) [Note: don't really know if this works for manual trans cars but I know it works on any of the AT cars with this inspection plate...AW trannys, not sure about ZF] Place a sizable screwdriver into the ring gear tooth closest to the bellhousing plate. With the other hand, use your ratchet/breaker bar with the appropriate socket on the pulley slowly and lock the screwdriver against the bellhousing as the engine and ring gear turns. Now, simply apply the necessary torque to break the bolt.  [See below for a better variation on this flywheel technique but remember the caution above regarding breaking the cast key in the crank.]

To tighten/torque the bolt on re-assembly, switch the screwdriver over to the other side of the bellhousing and repeat except in the opposite direction. [Another caveat:] Don't even *THINK* about attempting this ring gear technique above if you car has a Crankshaft Position sensor. This applies to all cars with LH 2.4 or greater. On these cars, what you have access to through the inspection plate on the bell housing is a thin sheetmetal metal ring with little square windows evenly spaced around the 360 dg with two windows missing at TDC and TDC + 180dg (or is it TDC - 90dg and TDC + 90dg? can't remember.) Either way, these little windows look like the perfect place to put a square shank screwdriver, but the sheetmetal ring is very weak and if you bend it even the slightest there's a good chance your fuel injection system will get highly confused. I believe that if the ring is even 1mm out of round, the pickup may miss one or more windows.

Another Flywheel Clamping Technique from Barret Flake:  A similar alternative to the one requiring the removal of the flywheel inspection plate: Remove or back out most of the length of the bolts (4) holding the flywheel inspection plate. Take the flat head screwdriver bit from your cordless screwdriver, I think they all are 1/4" hex drive, and slide it between the inspection plate and the bell housing with the flat head pushed in between the gear teeth. Now tighten the bolts to effectively clamp the screwdrive bit between the bell housing and the inspection plate.  With this set up you don't have to worry about holding the screwdriver in the teeth while trying to simultaneously loosen the big bolt. Also, you don't have to switch the screwdriver from one side of the housing to the other when you retighten the crank bolt. Worked like a charm for me. (93 940 B230FT/AW automatic)

[Yet Another Bolt Removal Technique [Chris Mullet]  Remove the splash shield. After all drive belts are removed, take the short wide one (from A/C) and hang it on the crank pulley only, so that it dangles down below the car. Slide about a 4 foot long board, under the air dam, through the hanging belt, and lodge the end under the cross member or oil pan. (I used a 2x6 with a belt I knew I was going to throw away. You could probably round the edges of the board, use a pipe, or just be a little careful if you are worried about hurting the belt.)
With one foot, push down on the front end of the board in front of the bumper, until you just start to compress the motor mounts. I donít think it will take much weight as you have quite a mechanical advantage.  While holding down on the board, take your breaker bar and solid hammer and knock the bolt loose.
You can use the same method to retorque the bolt.
Now, some people will say you run the risk of spinning the center part of the pulley inside the damped outer section. I guess thatís a possibility, but by pulling down firmly on the outer pulley, versus just holding it stationary with some other strap type holder, you increase the friction between the two....donít you?

Tightening the Crank Bolt with a Belt.  Crank Tightening.  [Tip from Carl Buxbaum] After replacing my timing belt, in order to tighten the crankshaft pulley bolt to 60N/M, I wrapped one of the old drivebelts around the innermost groove of the pulley, and notched a couple of teeth of the belt over the top of the water pump, where there are a couple of ridges that helped hold it there.  While grasping the belt with my left hand I was able to tighten the bolt to spec with my right without too much difficulty.

B230F Crank Bolt Torque on Re-installation. [Abe Crombie] Torque this bolt to 60N-m (45 ft-lb) plus an additional 60 degrees (1/6 turn).

Timing Belt Tips: Top Dead Center.  [Query]  How do I find TDC on my B230F when changing the timing belt?  [Response: Don Foster]  Pull plug #1 and stick your finger in the hole. Turn the front pulley with a socket wrench until you see the timing mark (front of timing belt cover and on front pulley) coming up on 0 degrees. If you feel no pressure in cylinder #1, then it's TDC but on the exhaust/intake stroke.
Continue turning the front pulley until you feel pressure on your finger as you approach 0 degrees. At  0 degress, you're at TDC for #1.
Remember that as you replace the belt, you should "fine tune" setting the crank and cam at their alignment marks (the I-shaft isn't important on a 700, but it's good practice to do it).

Timing Belt Tips in B23/B230.  [Tools and Aftermarket Belt Query] I am going to be replacing the timing belt and front engine seals, on a 91, 740, non-turbo, sedan, B230F engine. I have a few questions: Does anyone besides Kent-Moore make any of the Volvo Special Service Tools? Are aftermarket timing belts and seals okay on quality from somewhere like PepBoys? Will I need a Vibration Damper (Harmonic Balancer) puller for the Crankshaft?
[Response 1: Phil] Pep Boys is not known for good belts...at least the ones I've tried.  You're better off getting a name brand belt. Both TRW and Goodyear brands both have the markings on them and I'm sure other name brands do also. I don't know of a need for any special tools for the seal. You may want to get a set of those seal installing bushing pusher-inners. Or use a piece of pipe, a socket etc. Some folks here coat the OD of the seal with silicone sealant. I just use Compound 111 or you can use a little grease. Go easy, keep it straight.  [Response 2: Zee] Contitech is an aftermarket belt that my shop has used for decades. I liked the fact it had lines on it marking the positions of the timing gears. Great help on the install. (you will only see the lines for the two top gears, though, as the crankshaft marks are well out of sight at the 7 o'clock position.

Removing the A/C Compressor Belt.  [Tips from Justin Seiferth]  This can be tough. Loosen the 12mm holding bolt and the unscrew the 10mm tensioner bolt till there's a 1/4" of slack or so. If you still can't remove the belt, try unscrewing the 13mm mounting bolt just below the A/C compressor, this should give you enough slack. When putting the belt back on, make sure this mounting bolt is retightened. Put the A/C compressor belt onto the bottom of the crankshaft pulley and use the crankshaft bolt to turn the engine and inch the belt back on. It's a tight fit.

If you have a two piece timing belt cover, you can't remove the bottom half until you've taken off the crankshaft pulley. Be sure to put this cover back on after you've changed the belt and before you reinstall the pulley!

[Avoid These Goofs: Tips from Gary DiFrancesco] This is one of those goofs that not everyone wants to fess up to, but sharing it could save someone a lot of grief.  Several weeks ago, I replaced the timing belt in my '88 745T. The job seemed to go normally. A few weeks later I noticed what sounded like a worn bearing squawking away in the area of the tensioning pulley. I did not change the pulley when doing the belt since it seemed to be in good shape, and running smooth. When I removed the timing belt cover to replace the pulley, I found the compartment full of black fuzz. It was apparent the source of the fuzz was near the crank, and evidence of abrasion was visible on the outside edge of the timing belt.
To make a long story short, I reassembled the lower timing belt gear (on the crank) incorrectly. The outside flange for the timing belt gear was put on the shaft backwards. The subtle flare of this flange was pointing in and was rubbing the edge of the timing belt. I lost about 1/16" of the width of the timing belt in less than 400 miles. This error is not hard to do since the flange can go on the crankshaft both ways. Since I was about to go on a 1300 mile trip with the family, I immediately replaced the timing belt again and triple checked that the flanges were put on in the proper orientation.  The lesson here is obvious; double check your work before covering everything up. It might just save you some grief.

Timing Belt Marks [Tip from Ross Gunn] The OEM belt has some printed lines that you position at the timing marks on the three pulleys, but other than that not much difference.  You still have to find the timing marks and it can be a nuisance trying to position the belt on the marks on the pulleys.

[Tip from Justin Seiferth] If you have factory belt with alignment stripes on it, use a piecetiming belt7.gif (9489 bytes) of chalk to extend the alignment marks onto the front of your new belt. This will make installation just a little easier. The "alignment dot" on the lower right-hand pulley is hard to see. Stick a small screwdriver into the slot and line up with the dot on the pulley to see if the pulley and alignment dot are aligned correctly. The belt may be a bit small to get on easily- get an assistant to use a pipe wrench to compress the tensioner just a little.

[Timing Marks Tip from Mike] The crank timing mark is on the thin metal washer you removed after you removed the pulley.  It is keyed. I determine which tooth on the crank gear it lines up with and then line that gear tooth or valley up with the mark on the motor. Be sure to position the washer with the flanged side facing out or it will tear up your new timing belt.

[More from Ross Gunn] With the aftermarket belt, if there are no printed marks, just ensure the timing marks on the pulleys are lined up with the marks on the engine and you will be fine.  The tricky one is the intermediate shaft.  You will have to either look through the rad core with a light held between the rad and the block or hold a mirror directly in front of the timing mark and at 45 degrees so that you can look down from the top to see that the pulley mark and the mark on the plate behind are lined up.

It helps if you line up the cam pulley mark before removing the old belt and then be careful not to let the int shaft pulley move when installing the new one.  The mark on the plate behind the int shaft can be hard to find - try to locate it after lining up the cam pulley marks and before removing the old belt.  It would be wise to locate the crank pulley mark and corresponding mark on the block at the same time.

I suggest removing the old belt with a sharp knife to avoid disturbing the position of any pulleys.  Before removing the old belt, compress the spring on the tensioner and insert an appropriate pin in the hole in the rod inside the spring to retain it in the compressed position.  Remove the pin after the new belt is installed.  [Don Foster]  You know, of course, to first squeeze the tensioner back and lock the nut to hold it. Once the belt's in place release the lock nut so the tensioner presses against the belt. Tap it lightly -- this takes up the slack -- and lock the tensioner nut (37 lb.-ft).

[Tip from Steve Seekins] Rotate crank so that mark is about 9:00. Then put on belt - double marks straddle the crank mark (notch on outer plate). - be sure to get it right. Then put belt on intermediate shaft sprocket - line up mark and clip with a medium binder clip or one of those plastic woodworking spring clips. Do the same for the cam sprocket - you may need to use a wrench to turn the cam so the mark lines up with index mark on the belt - if the marks will not line up, you likely have the belt backwards - all three will only line up one way. Do not worry about rotating components individually - this is a non-interference engine.  Before you remove the clips, double check to make sure that the crank mark is lined up with belt marks. Release the tension roller, rotate crank 2X clockwise with wrench and tighten tension roller. Replace covers, pulley, belts, fan and you are finished. After a couple of hundred miles, remove rubber plug in timing cover, loosen tension roller and rotate crank CW 2X again and tighten. Don't touch it again for 50k miles.

Indexing the Timing Belt Markings.   [Tip from Randy] Lets assume the belt that is currently on there is correct. All you want to do is replace it with a new belt-  you want all the orientations to remain the same. Mark the current belt in some permanent way in relation to the gear. If the timing marks on the gears match up with an individual cog on the belt that will be perfect- if they don't you might have to make your own marks on the gear (fingernail polish comes to mind). The point is once you have the belt indexed to the gear arrangement you can easily remove it and you could put it right back on and be confident of getting it correct because you have the index marks on both the belt and the gears. So all you have to do is take the indexed belt off and carefully transfer your index marks on the old belt to the new one. Do this very carefully and be sure you match cog for cog as you move around the belt and mark the new belt exactly like the old one. BE CAREFUL to double-check the markings before going back to put it on. You might want to mark the front of the belt for reference in relation to the front of new belt. Some belts are already marked when new, but I always mark my own.   [Response 2:  Paul Kane] The intermediate shaft is no longer important.  I use white-out (correction fluid) to mark stuff.  The Cam mark is at 12:00, the notch on the belt guide on the crank is at about 10:30 and IS the cast mark on the block. BTW the notch in the center pulley aligns with the pointer on the lower cover.

Do I Wrap the Belt First Over the Crank or Cam Pulley?  [Don Foster]  My preference is bottom-end up -- replacing a timing belt, I mean.  The trick is, first, lining up the three pulleys to the timing marks (timing the I-shaft isn't important on a 740, but it's still good practice). Then start at the bottom by fitting the marked tooth into the gear at the timing mark, and wrapping the belt upwards. (I confess that I use small Vise-grips to loosly clamp the belt to the crank pulley.)  Wrap the belt around the intermediate-shaft pulley, around the cam pulley (observing alignment of the belt mark with the pulley timing mark) and slide it around the tensioner pulley.

Belt Adjustment After Installation in B23/B230.  [Response:  Stoney] I just got email from 2 dealer techs I know, with 18 and 20 years experience between them both are top VISTA techs and they said that the belt should be adjusted after 5-600 miles due to the fact that a new belt will stretch some in the first 1000 miles and they have seen a few "jump the cam gear"...  [Response 2: Don Foster] The tensioner has a spring in it which forces the idler against the belt to a predefined tension. But then, when you tighten the nut on the tensioner, you lock its position. The instant the belt stretches one hair, the tension is relaxed (because the tensioner's position is fixed, it can't move inward to maintain the force).   The tensioner, in this configuration, compensates for (adjusts for) the increased length from stretching -- to prevent it from jumping a tooth. It DOES NOT maintain a constant force on the belt.  It's assumed a new belt will "relax" a bit during when first used, so you must loosen the nut, allowing the spring to again reposition the idler. This "consumes" the extra length from stretching -- but then you tighten the nut again, locking the idler's position.   Ideally, there will be virtually NO tension on the belt, but also virtually NO "slop" in the belt.  Hence, after about 500 miles, more or less, remove the rubber plug from the timing belt cover, loosen the tensioner locknut, rock the crank slightly, and tighten and retorque the locknut.

Timing Belt Tensioner. [Question:]I recently acquired my 1986 760 turbo and was told by someone that the timing belt tensioner should be adjusted periodically. Could someone telll me when this is supposed to be done? I recently changed the timing belt and water pump (6000 miles ago). [Response:] It is wise to allow the tensioner to take up slack once a few thousand miles after belt is renewed. To do this you rotate engine in the normal direction (CW) 1/8 of a turn. This makes sure that belt has tension on the drive side between cam and crank gears. When you shut down engine it will often kick back afew degrees and tighten the backside of belt and then loosening tensioner bolt will allow belt to actually get looser. Then loosen the tensioner bolt one full turn and then retighten it to 37 ft-lbs. You will likely hear the tensioner jump as you loosen bolt.
New Tensioner Spring?  [Query:] Just bought a new timing belt tensioner for my 1985 740 Turbo. 226k miles and it has never been changed. The new tensioner I bought did not have a new tensioner spring attached to it. My question: Should a new tensioner spring have been included and/or do I need to change the tensioner spring with this many miles.  [Response: Don Foster] A new tensioner every 150k is the prevailing wisdom as I understand it.  No spring -- reuse the existing spring. You'll note a small hole in the shaft inside the spring. Compress the spring with old tensioner and slide a nail through the hole. Remove the tensioner and install the new one. Then pinch up with a big pair of Channelocks and remove the nail.  And at 225k miles, start thinking about the three front seals and water pump -- perfect time to do all that stuff.

Accessory Belt Tightening and Maintenance.  [Problem: Squeeling belts; how to set tension?] I'd be surprised if this wasn't simple belt squeal, but you can easily isolate the problem. Take a spray bottle of water (like your significant other's favourite plant mister) filled with water. With the engine on fast idle, spray a stream at each belt separately. The world will all of a sudden get real nice and quiet when you've hit the problem belt(s). If that doesn't alter the noise you've been noticing then you can look elsewhere (like bearings in the water pump, alternator, power steering, etc.).(PS. While you're in there with the plant mister, shoot the base of each injector with water. If the engine stumbles at all then that's a sign that the injector seals need replacing. Now get that plant mister back into the house before it's noticed missing.)
[Editor's Note: see http://www.dayco.com for a discussion on the various kinds of belt noise and causes.]
Tightening the belts will normally eliminate the squealing, but you don't want to overtighten lest you shorten the life of the water pump and/or alternator shaft bearings. The spec usually calls for a 1/4" max deflection at the mid-point of the longest span, but a heavy thumb can often get 1/4" even with the belt overtightened. I prefer to run my belts not too taught because of this and consequently a tendency for belt squeal is the price I pay. You can eliminate this by keeping the belts in top shape:
  -replace at the first sign of fatigue (fraying, hardening, cracking)
  -replace the main belts only in pairs to keep the tension uniform (any difference has to be adjusted with shims in the crank pulley)
  -try swapping the main belts periodically to change the tensioning
  -de-glaze the belts and pulleys (with sandpaper and/or emery cloth)
  -extend belt life and grip using belt dressing compound (available in spray cans from any good auto supplier) and to do the job properly take the belts off to
  soak them.
  -check that all pulleys are aligned (any belt deflection will only hasten belt wear, glazing and squealing)

[Response: Steve Ringlee] When you adjust the belt tension, take a look at how the adjuster mechanism works before you go at it.  Loosen the 13mm or 12mm lock nut on the belt side of the mechanism.  This unlocks the alternator or compressor and allows you to adjust tension with the long 10mm bolt parallel to the belt.  This latter bolt is only used to position the alternator.  Once you have set belt tension (3/16 to 5/15 inch or 5-10mm deflection) with the long bolt, lock the position with the 12 or 13mm bolt and back off a turn on the positioning bolt to unload it.  Don't forget to lock the nut or your belt tension will eventually fracture the adjusting bolt.

Alternator Belt Change.  [Query] I am attempting to replace the alternator belt on a 1988 740 GLE.  I am having problems removing the power steering belt so I can get at it.  I have loosened the bolt on the adjustment strap, but it will not budge.  Is there a pivot bolt somewhere that is not readily apparent. [Response 1:  Bruce] If this is a B230 engine, the steering belt does not need removed to replace the alternator belt. The  steering pump adjuster arm attached to the block sometimes needs loosened. The bolt going through the bottom of the steering pump itself sometimes needs loosening so it can pivot. You can also loosen the adjuster strap and back out the 10mm head adjuster,
then pull up on the steering belt will make the pump pivot and give belt slack.  [Response 2:  JT Charger]  You have to also loosen the 13m/m lock nut, before the 10m/m adjuster bolt can be loosened and backed off.

Alternator Belt Slips and Doesnít Charge.  [Query:]  My alternator belt is squeaking  and the alternator is not charging properly.  [Response: Don Willson] Check the harmonic balancer for the cause of squeeking. Paint a stripe from the hub to the rim. Run the car until you hear the squeek. Look at the stripe, if it is displaced replace the harmonic balancer. The rubber insert loosens and slips after a time.

960 Timing Belt Change in B6300 Series Engines.

960 Timing Belt Maintenance Intervals  [Query:] I've heard that the timing belt for the 960 series has to be changed more frequently than stated in the owner's manual. I was wondering if anyone was advised to replace the tensioner as well and if there was a bulletin from Volvo recommending changing the tensioner at 100,000 miles.   [Response:] Follow closely the recommended intervals. The '92 timing belt should have been changed at 20k miles and again at 40k miles. At that time a modification should have been done under warranty. This extends belt life another 10k miles, so the next belt change should be done at 70k miles then every 30k after that. This is only for the 1992 cars!
[Details from Abe Crombie:]  The 92's had an interval of 20K.  Volvo developed a damper assembly that fits onto exhaust cam that was retrofitted to 92's (if it was being taken to a dealer AND the technical service bulletin was performed) and was factory-fitted to 93's that allowed the 21mm wide belt to last 30K due to less cyclic loading on belt.  You can see the damper if is installed by looking through the holes in the cam gear on exhaust cam. The damper will make seeing the aluminum head through these holes difficult, especially if you compare to the intake cam pulley which is the same part but will have no damper fitted.  The 94's have a revised damper and some belt driven pulleys revised and a 23mm wide belt is used (belt is different length than 21mm belt) to give a 50K interval.  The 95-98 engines got a complete re-do of the belt drive and use a 28mm belt to give a 70K interval.

960 B6304 Timing Belt Change.  [Tip from Larry Borella] Recently there was an exchange posted concering replacement of 960 timing belts. I did mine Saturday. All things considered, it was easier than replacing the belts on my 740. Here are a few hints if you are inclined to do this yourself.
Start by removing the electric fan. Take out the two screws and then pull the wiring loom connectors from the shroud. Then you can just put the fan on top of the overflow reservoir/ac dryer and you don't have to take the battery out etc.
Remove the acc belt (I use a 3/4 in adapter on my 1/2 drive breaker bar). Take off front cover. I changed the plugs at the same time so I left the plugs out so it is easier to turn the crankshaft pulley to align the timing marks on the cam pulleys. I used either an 1 and 1/4 socket to turn the crank. The notch on the crankshaft pulley is hard to find. You have to look straight down; its on the back side hub of the pulley. The matching mark is on the back of the plastic timing belt cover (which is not removed).  Get them all lined up, then remove the top bolt from the belt tensioner. Then back out the bottom bolt about 1/4 to 1/2 inch. Then you can twist the tensioner which will pop the plunger from its position. Then you can take it off and remove the belt (there is a metal guard held on by two bolt behind the crankshaft pulley that must be removed from under the car).

Put the new belt on. The manual says start at the crankshaft pulley then work up and around in a counter clockwise direction.  You have to compress the tensioner before installation. I put it in a vise (the vise has to open about 6 inches to hold the tensioner. If you were hard pressed, I think you could do this in a large c-clamp. The resistance on the tensioner is significant. I found that turning the vise about a 1/4 turn then waiting about 3 to 4 minutes before the next turn worked well. When you get it compressed, there is a keeper hole (make sure you line up the hole before you compress the tensioner) into which you must insert a pin to hold it in the compressed position. I used a 1/16 inch drill bit.  Then you put the tensioner back on. I found that putting the top bolt in first worked best. You can push the bottom of the tensioner to get the bottom bold lined up. If you do it the other way, you have try to pull the tensioner (working from the passenger side of the car).
Now you rotate the engine two revolutions and check the alignment. Guess what. Mine didn't line up as well as I would have liked. The cam pulleys were fine but the crankshaft pulley was slightly "advanced" (maybe 5 degrees). I did it all again.
Same result. I took it off and did it a third time making doubly sure I had all the belt lugs where they should be.
Same result. I spun the engine with the starter (with the plugs still out). All seemed well. I bolted her up, put in the Bosch +4's, started the car and went for a test drive. Runs fine.
Two notes of caution. If you leave the plugs out for anything, put the ignition coil cover back on. Those openings look just like a funnel designed to put a dropped screw/nut into the cylinder. Second, don't leave plugs in too long between changes. If they seize up and break off when you try to remove them (as I have heard happens fairly regularly), you got real problems. I put penetrating oil around mine before I removed them and even so, they were uncomfortably tight with only 50 k on the car.

More 960 Timing Belt Instructions  [Procedure from  Larry Jacobson]

This has play by play instructions about the 960 timing belt.

Today was the day to attack the timing belt on my 1996 965.  I've changed lots of timing belts on lots of cars, but this was the first time I dug into the 2.9 ltr Volvo.  Apparently there are no worthwhile aftermarket manuals for this car.  I am grateful to an herein unnamed (for his own protection) list member for snailmailing me a copy of the appropriate section on a genuine honest-to-goodness, bona fide and sanctified Volvo shop manual.

The bottom line was it took me 2.5 hours.  It is not as difficult as the belt on the 2.3 ltr 4 cyl engine.  No special tools are required.  I'm sure I could do it again in 1.5 hours now that I know how.  The following are my observations.

If you are going to do this job plan to change the oil and filter at the same time, inspect the front brake pads, change the serpentine accessories belt, and if you suspect the integrity of your water pump ... do that too.  You can't get back to the water pump without first taking out the timing belt.

Before starting you will need common mechanics tools, ratchets, a variety of extensions, a big vice or a 6 inch C clamp, and probably a big pipe wrench.  A dental mirror would be handy and some very good lighting.  There are some things that are difficult to see.

1) Jack up the front end of the car and suspend it on jack stands. Probably best to remove the front wheels.  Check the brake pads while you are there.  You are going to need enough room to get underneath to work.

2) Remove the belly pan that covers the oil filter.  You might want to change the oil and filter now.

3) You're going to need two pins that will be used to hold things in place.  Locate them now before you need them.  a) Take a 16 penny common nail and cut it to 1 inch so that you have the head plus one inch.  It will be used to hold the serpentine/accessory belt tensioner in place while you take off the belt.  b) Locate a 3 penny common nail.  It will be used to hold the timing belt tensioner in place while you reinstall it.  Don't cut the 3 penny nail.

4)  There is no need to remove the electric fan.

5)  Draw a picture of how the serpentine belt is routed.  If you don't know how it came off it is going to be real difficult to get it right when you try to put the new one back on.  Now remove the serpentine belt tensioner.  There is a tapered square hole that will fit 3/4 inch, 1/2 inch, and 3/8 in square drive.  However you'll need a very short extension to fit deep enough into that hole.  I couldn't find the right size so I just took a large pipe wrench and moved the tensioner.  Line up
the holes and slip the cut off 16 penny nail to hold it in place.

Remove the two 12 mm bolts that hold the tensioner in place and remove
the tensioner.  Now remove the serpentine belt.

6) Remove the timing belt cover.  It is held on by only one 12 mm bolt.

7) Crawl under the car and locate the shiny metal 'vibration damper guard'.  It's held on my two 10 mm bolts.  Unscrew those bolt and remove the shiny cover to expose the crankshaft gear and the lower end of the timing belt.

8) There is no need to remove the vibration damper.  If you turn it slowly using the small bolts you can turn the engine to line up the timing marks.  Turn it clockwise while looking at the front of the engine.  The cam timing marks are obvious.  The crank timing mark is not obvious.  I used some of my daughter's silver nail polish to mark the crank's relationship to the block and the timing marks on the two cams. I also marked the existing timing belt so that if worst came to worst I could count the cogs between the various timing marks.

9) Tensioner efficiency:  Before you take off the tensioner and the timing belt, take a moment to notice the tension on the belt between the exhaust cam and the water pump.  It seems to move about 1/4 inch with about 10 lbs lateral pressure.  This is purely a guess based on what I thought it felt like.

10) Remove the tensioner by a) slacking the two 12 mm bolts, b) removing the upper bolt, c) rotating the tensioner clockwise a little, d) removing the bottom bolt and lifting out the tensioner.

11) Remove the timing belt by first removing the two 10 mm bolts that hold the plastic housing on the top of the shroud at the top on the engine.  No need to actually remove this top shroud.  With the bolts out it can be moved enough to get the belt out.  Remove the belt off the cams.  Then get under the car and very carefully work the belt off the crankshaft gear.  ...remembering how you got it off because it's like a Chinese puzzle to get the new belt back on.

12) Take a good look at the tensioner assembly.  It is an hydraulic affair and it should not be leaking oil.  If it is leaking you need to replace it.  That tensioner fails the belt will jump cogs and the motor will be destroyed.

13) Compress the plunger back into the tensioner.  First remove the white nylon positioning ring.  Line up the three little holes so you can place the keeper through them to allow you to reinstall the tensioner. A vice would work well to compress the tensioner.  My vice was not large enough so I used a 6 inch C clamp.  Compress the plunger a quarter turn at a time allowing it to 'rest' between twists.  When the plunger is all the way flush with the housing push a 3 penny common nail into the hole with the head of the nail facing out so you can pull the nail out when the tensioner has been reinstalled.  Place the nylon guide back on the tensioner.  (a new one probably came with the new timing belt)

14) Inspect all the idlers for smooth operation.  Inspect the water pump for leaks.  This is the time to change the water pump if it isn't in good shape.

15) Install the new belt.  I found it was easiest to snake the belt down to the crankshaft gear before trying to place it on any of the other gears or idlers.  Crawl under the car with a good light to work the belt on to the crankshaft gear without crimping it in any way.  Once it's on the crankshaft gear, then put it on the intake cam and remove all the slack between crank and intake cam gear.  Then do exhaust cam and then water pump and finally the idlers where the tensioner goes.  You want all the slack at the tensioner idlers.

16)  Install the tensioner.  Tougher than it first looks.  There's not much room between the tensioner and the fan for fat fingers.  Locate the top bolt first and get it started.  Then do the bottom one.  Make sure the tensioner seats itself flush on the front on the engine and torque it down.  Volvo says 18 ft pounds (25 Nm).  I couldn't get a torque wrench in there.  Regardless, that's not a lot of torque.

17)  Critical point:  carefully inspect all your timing marks.  Is there slack anywhere except around the tensioner?  Is the belt fully seated on each gear?  If everything's OK, take some pliers and pull out the 3 penny nail that has been holding in the plunger on the tensioner.  It comes out fairly easy.  The tensioner will ease itself back into position and will take up all the slack on the tensioner side of the engine.  Inspect by feeling the tension between the exhaust cam and the water pump.  Does it feel about as it did before you took the belt off. Are the timing marks still where they are supposed to be?

18) Crawl underneath to make sure the belt is seated on the crankshaft gear.  If it is in place, reinstall the vibration damper guard. Reinstall the splashguard that covers the oil filter.

19) Reinstall the two 10 mm bolts that hold the top of the cam belt shroud on the top of the engine.

20)  Volvo recommends you make the crank turn two complete revolutions to make sure all the timing marks are still in place.  That's more difficult than it sounds.  I skipped that step and crossed my fingers.
21)  Reinstall the timing belt cover.

22)  Install the Serpentine/Accessories belt tensioner.  While you are doing that snake the new belt around the accessories and locate the tensioner and bolt it down.  Be very careful to be sure the serpentine belt is seated in the middle of all the pulleys on its route.  When you are sure it is correctly positioned turn the tensioner just a little and remove the cut off 16 penny nail that you installed at the beginning of this operation, allowing the tensioner to take up all the slack in the

23) Carefully inspect the engine bay for tools and stuff.

24)  Voila!  You have successfully changed the timing belt and the serpentine belt.

Parts:  Timing belt is Volvo part 271876.  Serpentine belt is Volvo part 9146106.  It is stamped Made in USA Dayco.  You can probably find it cheaper in a parts store under the Dayco brand name.

960 Engine Pulley Timing Marks.  [Query] I saw your posting on the internet about changing the timing belt, and wonder if you could help me with a question.   I changed the belt on my '94 960 and put the new belt on just like the old one came off. The car ran just fine, so I should have left it alone.  However, I noticed that the timing marks on the two camshafts did not align as the service manual showed that they should. The intake mark was four teeth off, and the exhaust was one tooth off. So I changed them to what the book showed, but the car ran ragged.  I changed them back, but got confused somewhere along the line. Now I can't get them aligned at all, and the engine won't rotate all the way because of the valve/piston interference (I didn't crank it, just turned the motor gently with a socket wrench, so I haven't damaged the internals of the engine).  The service manual says to align the marks on the camshafts with the indicators on the cover plate, and to align the mark on the crank pulley with the oil pump housing. I've studied the crank pulley and can't find a mark anywhere on it for reference.  Do you know how to determine the correct position of the crank shaft when aligning the timing belt?
[Response: Jim Bowers] Sounds like someone has replaced seals, had the pulleys off and didn't take the trouble to put them back on with the marks lined up. Now the only way to get them set properly is to use the Volvo alignment tools. There is one that holds the cam shafts and one that holds the crank. The camshaft tool is about $300 and the crankshaft is about $60 from your friendly Volvo parts dealer if he can get them in a reasonable time. I suggest you take the car to the dealer and ask him to set the timing and be sure to tell them to make sure they line up the marks so you won't have this problem next time.

960 Serpentine Belt Installation.  [Query:] My son's 960 needs a new serpentine belt and I planned to install it.  Has anyone had this experience and how difficult is it?  [Response: Bruce] It is not difficult to install. You can remove the three top screws holding the electrical fan into the top of the radiator. Pick the fan assembly up and place it along side the exhaust manifold. This gives more room when replacing the belt. Take a good look or write down how the belt travels around all of the pulleys first. You will need a 3/4" or a 3/8" wrench to move the belt  tensioner. Depends on the year of the car. The tensioner has a 3/8" hole for a 3/8" ratchet to be inserted and move the tensioner assembly as to release the belt tension. There will be a small hole to insert a 1/8" or 3/16" cotter pin in to hold the tensioner in the released position. Remember how the old belt is routed. It can be installed in different configurations but only one will be correct and fit properly. Remove the old belt and install the new belt. Release the tensioner and you are all done. [Response 2: J. Charger] a smart guy could "unload" the spring loaded tensioner with a very large set of channel lock pliers, then change the belt, with out special tools.  on the other hand, the adapter tool needed is probably less than $10, from Volvo, to adapt a 1/2" drive ratchet to the tensioner.

960 Rear Cam Seal Repair.  See 960 Rear Cam Seal Repair.

B234 Timing Belt: New Oil Pump Bolt Needed.  [Tip from Abe Crombie]  When replacing the timing or balance belts, replace the bolt on the oil pump pulley. These have been known to break and the belt comes off and you bend valves. It doesn't happen until you replace belt and the stress of new tight belt can pop the head off the bolt and then it's bad news.  [Confirmation from Paul Bente]  When replacing the timing belt at the recommended 50,000 mile intervals on B234F motors (16-valve interference head), I highly recommend that the oil pump pulley (driven by the toothed timing belt) be removed, the pulley carefully checked for cracks and defects, the bolt replaced with a new one from Volvo, and torqued carefully to specifications. If you must use a non-Volvo bolt, be absolutely sure it is of the proper grade from a reliable source. If your motor has over 100,000 miles I urge you to check it now and not wait. If you wonder why, read the sad story below. Acquired my 91 940GLE from my brother-in-law at 137,000 miles. It had documented service by the Volvo dealer at all recommended intervals. After driving across country, the scheduled 150,000 timing belt replacement and other maintenance was done at 148,200 by a Volvo factory trained (presently independent) mechanic. Within 1,000 miles the engine failed. Symptoms were instant, complete loss of power, and check engine light on. Fortunately it happened at low speed on a two lane road next to a wide shoulder. If it had
happened on the #1 lane of a crowded freeway at 70 mph, I hope I'd still be around to appreciate Volvo unibody integrity. Teardown of the engine showed the bolt holding the oil pump pulley failed, pulley jumped off the shaft, engine lost timing, valves crashed into pistons -what a mess. Microscopic (40X)
examination of the bolt showed classic tensile failure at the bolt head with no evidence of defects or inclusions in the bolt. Conclusion: bolt was probably overtorqued during assembly. I also observed that the cast iron oil pump pulley was also cracked starting at the stress concentration point on the inside
diameter and progressing 2/3 of the way to one of the holes in the pulley. The crack was partially rusted, indicating slow propagation. This was not a cause of the bolt failure, but I estimate the pulley would have failed within another 50K miles. Since other B234F motors of similar vintage may also have been similarly overtorqued in assembly I strongly sugggest you check yours out now. Don't wait for it to fail.

B234 Seals:  Counterhold Tool.  [Query:]  I am trying to find out where to obtain a balance shaft pulley counter hold tool (5362).  I recently replaced the balance shaft seals but they are still leaking. I am afraid to try it again without the proper tool.  [Response: Rob Abel]  I got mine at the Volvo dealer, and wouldn't do the job without it. One DIY timing belt and it's paid for.

Crankcase Ventilation: A Treatise.  [Don Foster]

A normal byproduct of a normal engine operation is "blow-by", or a slight leakage of combustion gases by the piston rings and into the crankcase. It is very desirable to release this pressure. Years ago it was simply vented into the atmosphere. Later, it was vented into the intake system through the air filter. More recently, it is forcibly removed using engine vacuum and certain controls. This system burns the vapors, reducing the environmental problems.
On the Volvo B21/23/230 engines, this is accomplished with the contraption we call the "flame trap" or guard,but the system also includes a flame arrestor, the oil separator, some hoses, and a fitting on the intake manifold.
Excess pressure can force oil past seals. Excess pressure can damage seals and gaskets. Excess pressure gunks up engines. Excess pressure vents into the atmosphere, which is not good for the environment. On the 240 with the B230, excess pressure can pop the plug outta the back of the cylinder head (happened to my daughter and she won't let me forget it).  Crankcase vacuum is directed through the "flame trap" system. During normal driving, engine vacuum is from the intake manifold (upstream of the throttle), through the top of the flame trap, through the flame arrestor, through the oil separator (a.k.a. "breather box") and to the crankcase.
During idle, when there's insufficient vacuum, additional vacuum comes through a small hose attached to the flame trap and to a small fitting in the center of the intake manifold.
The flame trap consists of a lower hose (which sits directly on the oil separator), the upper hose (which has a large and a small fitting for vacuum hoses), and the flame arrestor. The gases in the crankcase are highly combustible, so it's very important to prevent igniting them with a backfire. (If you did, you'd be replacing all your engine seals and gaskets, or maybe your car.) The flame arrestor will absorb the thermal energy from a backfire and quench a flame front. (Note -- this is a very old technique, used during the last century in coalmines when the miners had acetylene lanterns.) So it blocks flames but passes gas.
The oil separator is bolted to the block and is a single molded plastic unit. I don't know how to take one apart, although I've successfully cleaned out several of them. They're cheap enough that you might buy a new one without a second mortgage.  The function of the separator is to allow the oil vapor and droplets some time and space to coalesce into larger drops and flow back to the sump. The separator has two openings into the block -- one for vapors to rise through, and one for the oil return. The oil return opening has a hose that MUST remain in place -- don't dislodge it, or you'll be pulling the pan.
The flame trap is located (buried is more truthful) under the intake manifold between headers 3 and 4. It sits directly on the oil separator. Cleaning the system includes cleaning or replacing the top 'n bottom hoses, the brass or plastic arrestor, the large hose to the intake manifold, the small hose, and the small fitting. And the oil separator.   The small hose and small fitting (in the manifold) are famous for plugging. Clean the fitting, replace the hose.  Inspect the arrestor (old style=brass, new style=plastic) to confirm the passages are clean and free. If not, either wash or replace -- they're only a buck, or so. Buy a handful.  Volvo sells a "kit" which includes the top 'n bottom molded hoses and the arrestor. It's worth the few dollars.
A coupla quick checks....... With the engine idling, pull the small hose off the flame trap and feel for vacuum -- it should be there.  Pull the trap off the oil separator and observe (or feel) the separator to confirm that crankcase vapors are streaming up.
Do the "jiggle test" -- with the engine idling, loosen the cap but leave it in place. If it sits there quietly then there's enough vacuum to hold the cap. But if it jiggles and bounces, you have insufficient vacuum (and maybe too much pressure). [Editor's Note: This test is reliable only with the earlier metal cap, not the plastic cap.]  It's conceivable that a partially blocked system might provide slight vacuum, requiring only a little finger pressure to hold the cap down. If so, I'd start thinking about some preventive maintenance.
For the technically-inclined....... I built an adapter and measured the crankcase vacuum at idle. All four of my registered Volvos ('82 245 with 335k; '82 245 turbo with 130k; '85 245 with 235k; and '91 740 with 180k) measured from 1.75 to 2.25" of water, vacuum.

Flame Trap & Crankcase Ventilation Questions.
Basic Crankcase Ventilation Maintenance:  [Response: Don Foster]

[Query:] How much suction should I expect with the vent system working properly? Should the oil cap suck down hard, or is a slight jiggle with what appears as an overall suction enough? [Response 1:]   In order for the 'jiggle' test to work, the filler cap needs to have a good gasket. These gaskets only last a year or so on the turbos, then they get hard and brittle. Even with some crankcase vacuum, the engine vibration will make them jiggle. Replace the rubber gasket and try the test again - let us know the results.
[Response 2:] Even without the 'flame trap', the positive crankcase ventilation system can become clogged with hard deposits. The hoses themselves can become restricted, or various ports and orifices can become clogged or the oil vapor separator on the side of the block can  become clogged. Often, the hoses, when clogged and old just need to be replaced. (BTW  - running the engine with synthetic oil will help prevent clogging of the PCV system because the synthetic oil has a much higher vapor point so that you do not get as much oil vapor condensing and hardening in the system. And what vapor does exist does not coke as easily to form the hard deposits.)  The 'jiggle test' is to loosen but do not remove the oil filler cap while the engine is running. If there is negative pressure in the crankcase, it will be sucked down to the valve cover and will sit still. If there is positive pressure in the crankcase, the cap will dance or 'jiggle' on top  of the valve cover as the pressure escapes.
[Response 3:] I just purchased a 87 745 turbo that was blowing oil from the oil fill cap on the valve cover. I took a rather heavy handed approach. I bought a can of Gunk motor flush. I warmed the motor, turned the motor off and then poured the motor flush down the large hose leading to the flame trap. Initially, the motor flush would not move through the flame trap. Within a few min. it was running through the hose and into the flame trap as fast as I could pour it. I then blew through the hose with compressed air, started the motor and let it idle a few min. Then  drained the oil and changed the oil filter. Just to make sure all of the motor flush was out, I  again blew through the flame trap with compressed air. I plan to drive the car about 1,000 miles and replace the oil and filter again. I know this is probably sacrilege to some but I think this is the fix. The motor is no longer blowing oil out the breather. [Response 4: Don Foster]  I had luck with carb cleaner, a coat hanger, and compressed air. I sprayed the cleaner in and let it soak 45 minutes before blasting the crud through with compressed air.   I followed with a quart of Gunk Motor Flush (I think it's only kerosene or diesel fuel).  Then I drove the car 25 miles and changed the oil. In my opinion, if you tried to pour anything down there while the engine's idling, you'd end up wearing most of it.  The only reason I didn't remove the oil separator is because on an '82, with K-jet, the separator's buried. It would have been a two-day job to remove and clean it. On the B230 engine, it's a half-hour job to do it correctly.
[Tip from Ralph Haber] This may seem obvious, but can be easily overlooked. During a recent oil change and flame trap replacement, I decided to check for vacuum at the FT fitting. There wasn't any. Closer inspection revealed that the hose and intake manifold nipple were completely sealed off by a 10 year accumulation of dried oil/carbon and other yuk. No vacuum was  present at the flame trap fitting. Replacing the hose and drilling out the nipple gunk corrected the problem. This was on a B230F engine in a 89 744GL with 189K on it. This is real easy to check and can be rectified  with a minimum of effort. Untreated, it may allow unwanted pressure to accumulate in the crankcase leading to oil leaks and blown seals.  [Related Tip from Steve Roop] The intake manifold vacuum fitting (small) going to the flame trap was hopelessly clogged.  After struggling with trying to clear the blockage and wanting to get to bed in this century, I found that a 3/32 drill bit, turned slowly,  would clean out the nipple perfectly (of course I removed the fitting from the intake manifold first!).  Anyway, it really speeds up the cleaning process and I now pass the jiggle test again.  [Tip from Mike W.] If the manifold fitting is plugged, the hose between it and the flame trap surely is also, and should be replaced.
[Query:]  Why not just leave out the flame trap?  [Response: Editor]  The flame trap prevents any engine backfires from reaching blowby gases in the crankcase, which would otherwise cause catastrophic results.  It is an important part of the engine and must be left in place.  Since cleaning it is not hard, there is no reason to remove it.
[Query: Stuck Flame Trap]  In the Volvo dealership where I worked as a tech for quit a long time, what we did to get the flame trap out was take your screw gun and shoot a small screw partially into the center hole in the lil bugger. This gives you a handle to pull it out with and makes it very easy to change. Otherwise you'll screw around all day trying to get it out.

Excess Crankcase Pressure.  [Query:] My Volvo has recently developed a case of extreme crankcase pressure. I noted on more than one occasion that the oil dip-stick had been blown up from the tube, spraying oil throughout the engine compartment. I replaced the original flame-trap element with the newer factory plastic resin type, cleaned the manifold orfices, changed the oil and filter and checked the results. Once again, the oil dip-stick was blown up, and another oil-bath was applied to the engine compartment. The only way I can make he dipstick remain in place is to use an elastic cord holding the stick to the manifold. I am obviously missing something here... How else can I relieve this pressure?  [Response 1:Don Foster] On your engine, the major components of the crankcase ventilation system needing attention are:

Each of these items should be inspected, cleaned, or replaced.  Volvo sells a replacement flame trap kit that may be more useful than trying to recover a  badly varnished (and hardened) housing. The small vacuum hose, and the manifold fitting, are notorious for becoming plugged. The hose you replace for $0.25. The fitting can be reamed out with a piece of wire and carb cleaner.
The breather box has been mentioned several times -- it can be removed carefully, washed out, and reinstalled. (Be careful to NOT tug on the hose inside the block that meets this hose.)   If these are all fine and you have vacuum at the two vacuum lines, then you might have a serious engine problem, such as a bad ring. This is very rare with that engine.
Turbo Oil Breather Box Notes:  [Editor's Note:  See Michael Ponte's excellent tips and illustrations on oil breather box maintenance at http://www.mikeponte.com/volvo/oiltrap.htm

Excess Crankcase Pressure? Dipstick O-Ring Fails.  [Comment from Randy:] I had what I thought was an excessive pressure problem in my 90 740 with the b230f. Had the same problem with the dipstick blowing out and bathing the engine compartment in oil. The flametrap and all the plumbing was not restricted. I even went to far as to hook up a pressure gauge to the crankcase! Findings?? There wasn't the tremendous pressure I expected to find. Solution?? Replaced the O-ring on the dipstick- problem solved. It is worth the investment in a new O-ring to check it out.

Oil Breather Box Beneath Flame Trap.  [Query:]  My crankcase pressure is still high, even after cleaning the flame trap.  How do I clean the breather box?  [Response 1:] The black box under the flame trap is often called a "breather box" -- I don't know what Volvo's official name for it is. [Editor's Note: See http://www.mikeponte.com/volvo/oiltrap.htm  But its function is to provide a low-velocity space for fine oil mist and droplets to collect (or coalesce) into larger drops that can flow back into the crankcase.  Yes, it can get clogged, and can be removed and replaced. It can also be removed, cleaned, and reinstalled. Others have wisely pointed out that there is a hose connected to this box inside the block. This hose goes back down to the sump, and is held in place with clips. When removing the box, be careful to NOT disturb or yank this hose.   I cleaned it out on my '86 245GL -- removing it was a minor job. As I recall, I had to twist a bit to get the socket in there, but the real problem was just seeing what I was doing. It actually went easily.   As I recall, there's an O-ring where the box fits against the block -- you might want to buy a replacement first.  [Response 2:]  Try running some Gunk Motor Flush (a kerosene solvent/detergent used just before an oil change) down into the breather box through the flame trap tube.  It may dislodge any crud inside the box and free up the drain into the crankcase.  Just make sure you change the oil immediately after you do this.  [Response: Ivan] To anyone wondering about the legitimacy of the "oil fill cap wiggle test", I can vouch for its validity. On my '86 B230FT, changing all the clogged PCV hoses did not affect the vacuum at the fill cap, but changing the oil trap sure did. The old oil trap weighed about twice as much as the new, and was visibly full of crud. Changing it was pretty easy, even without removing the intake manifold, but do be sure to buy the O-ring that goes with it, and some liquid gasket.  The results are well worth the $37: the turbo is no longer blowing oil past its seals (I think), the car idles a little more smoothly, and the oil fill cap stays happily in place at idle.

Finding Engine Oil Leaks. Rear Main Seal. Auto supply stores (larger ones such as NAPA) sell an ~$5 1-2 oz. bottle of oil leak dye. Clean/wipe existing oil from engine etc., add to engine oil, run for 50-100 miles and inspect for leaks with a black light. The "dye" fluoresces brightly when exposed to black light.  Buy a fluorescent black light at Walmart; General Electric makes both a BrightStick (24 inches) and a smaller blacklight unit, both AC powered and both inexpensive.

[Look for leaks at:] Regarding oil leaks on 89 744T: Prime places to look are cam cover, distributor O rings, turbocharger return line (at turbo and the O ring into the engine) and, like Letterman's top 10, Number 1: Oil Filter mounting O ring(s).
[Editor's Note:]  It helps to have a clean engine when you are looking for leaks.  See below for tips on cleaning your engine.

Cleaning Your Engine. [Editor's Note:]  It helps to have a clean engine when you are looking for leaks.  Cover the distributor with plastic wrap.  Put a piece of well-chewed chewing gum on top of the little vent hole on your brake fluid reservoir.  Use Simple Green or a water-based degreaser on stubborn spots, then use the "tire cleaner/degreaser" setting at your local self-carwash to cover the engine with cleaner. Try not to spray into the alternator, ABS unit or distributor.  Let it soak for a while, scrubbing with a brush where necessary.  Use the low-pressure wash to remove the deposits.   Do this at least once per year and you will find it much easier to both work on the engine and diagnose problems.

Replacing Oil Seals.

Removal Cautions:

[What have you used to pull the old seals out and press the new ones in?] It's pretty straightforward as long as you have all the timing marks lined up. Just keep that little detail in mind for re-installing the belt. As far as removing the seals go, I have a little tool in my tool cab that I don't know the origin of that slightly resembles a dental probe. It's a straight, ice pick looking thing with a 90 deg bend at the working end. I simply reach back behind the edge of the seals, work my way around and pry 'em out...being careful not to nick any of the sealing surfaces. [A cautionary tale] I just did a 120K mile service on our '90 745 (B230F). I did the oil seals (and water pump--how's that for anal!) as long as I was doing the timing belt. Two things about that. First, a good impact wrench makes the crankshaft pulley nut a breeze, even with an automatic trans. The crankshaft barely moves, even with nothing holding it in place. Now the bad news. I think I may have slightly scratched the camshaft in pulling the seal. There is oil on the water pump coming from the vicinity of the top, front of the head, on the order of a drop or two per minute. To be sure I didn't screw it up, I redid both valve cover gasket and camshaft seal the next day (cursing all the way). I felt a slight scratch on the shaft with a q-tip the second time, and buffed the cam with fine emery paper and 1200 grit finishing paper. Anyway, it still seems to leak.

Pressing in the New Seal:

Installation is NOT the reverse of removal. I used my hands to gently but forcefully press the seals in place. Worked for me... at least they're still holding after 10k miles. [Response: Paul Grimshaw]  There is a special Volvo Tool (PN 9995025-5) that is used to press the oil seal into place.  Is the tool necessary?  Well, the seal is fairly fragile, with an inner spiral spring that can be easily bent.  The seal costs almost as much as the press tool, so I'll let you decide the cost/benefit.  As for tool necessity to install the seal, if you are careful it can be done without the press.
[Response: Rob Abel]  That "special tool" is just a socket-like contraption that fits over the crank, then has a bolt which threads to the crank - purpose to evenly, slowly and gently press in crank seal. You can do the same thing with homemade tubing, pvc, pipe, or whatever has the proper diameter and two square ends. On the crankshaft, the tube should fit over the crank, but not be so large as to be larger than the crank seal. Ideally, the outside diameter should be just smaller than od of crank seal, and inside diameter just larger than od of crankshaft.
Load the spring into the lips of the seal with some grease so it won't fall out, lube the lips of the seal,
start it in by hand evenly, then gently tap it into place using the "seal installer" you've found/made/stolen/borrowed or whatever, and a wooden block. The cam and auxiliary shaft are the same diameter, same seal, so you only need 2 installers, one for cam and aux., and one for crank seal. Just be patient and go slowly, and you'll get them in right.
Some prefer to use RTV sealer on the outside of the seal, others don't. If you do use a sealer, use brake
cleaner to clean up all surfaces first.
[Another tip:]  I bought a PVC coupling that was close to the same size. I used the crankshaft bolt and a piece of flat iron to press it in. Went in squarely.  [Another: John B.] Use a seal pusher you can make out of copper tubing or pvc tubing...use a rubber mallet on the pusher to tap the new seals in.

Lubricating the Seal Prior to Installation:

[Fix:] did you lube the sealing lips of the oil seal with engine oil prior to installation? I've learned the hard way; it doesn't take long to maim a dry seal. [Fix:] [See also Cam Seal Replacement]  Make sure you put sealant on the sides of the front bearing cap, and on top of the gasket in the same places, also put sealant under the cap on the head mating surface between the bearing and the seal. If the leak is indeed through the seal, you could try moving it in or out a little or get a new seal with two "lips" (no idea what it's called...).I always do exactly as all the books say not to, I remove the front bearing cap and take the old seal out, then I apply oil to the outside of the new one to avoid squeezing it and put it in. Then I apply sealant on the bearing cap, just in front of the bearing surface, and put it back.  [Another response:]  Two common problems installing seals are rolling over the seal lip, and failing to pre-lube the lip and crank surface. I hope you considered both of these.

Location of New Seal:

[Query:] I'm still at a loss as to how deep to press in the main seal - should it be flush with the housing or jammed all the way in? [Response : Rob Abel] See if you can get a good look at the surface of the crankshaft which was in contact with the lips of the old seal. Sometimes, grit gets in there and causes ridges to wear in the crankshaft. Because of this, many will seat their seals a bit deeper, to offset the lips of the seal from the more abrasive surface of the scratched crankshaft. The idea is to seat the seal so it contacts the crankshaft at a smooth point. Doesn't really matter whether it's flush or all the way in. I would put it just inside of flush if you can, but it depends on the cranks surface. [Another:]  If you install the seal about 1/16"-1/8" further in than the old seal, the lip will have a fresh surface on the crank.  [Tip from Washington Volvo Club] Care is required when installing front oil sealsóDONíT push in too far. DON'T get it more than 1/16 to 1/8 in. past flush.

Procedural Tips:

More on Engine Seal Installation.  [Query:] I'm doing my timing belt and want to replace the seals. I can't bend, push, force or cajole the new cam and idler seals in place. I've tried everything I can think of.  Are there any tricks?  The old ones were orange reddish, the new are black and seem slightly larger.  [Response 1: Alan C.] Just my 2 cents worth having just gone through this, twice for the intermediate shaft seal. It leaked after installation. When I checked it with a mirror before the second replacement I saw that the lip had rolled out on the bottom causing the leak. Use a mirror and flashlight to be sure the lip is not rolled out. Volvo told me to put white grease in the area that contacts the shaft but nothing on the outside of the seal. They also told me that they redesigned the seals, that is why the new ones are black. Make sure there are no pieces of the old seal in the recess as it would make it hard to press in the new one. I found it helpful to gently slide the seal over the shaft while rotating it to be sure the lip does not roll over. Find/make a press tool from pvc pipe/coupling and use the pulley bolt to press in the seal. Take your time and check the progress to make sure it is going in straight and do not seat it too far in. I do not think it is a good idea to pound in the seal as this might cause the spring on the inside to pop out. Hope this helps. [Response 2: Don Foster] Last time I did a cam seal I pulled the valve cover and removed the front bearing cap, which also retains the seal.  Be careful of the valve cover gasket. The I-shaft seal, as I recall, pried out easily, and the new one pressed in -- a tad firmly (which is comforting).  Don't forget to clean everything thoroughly, and lube the seal lip and shaft surfaces before you install the seal. Also, examine carefully to be certain you haven't "rolled" the seal lip during installation -- easy to do, easy to miss.  [Response 3: Henry Cordova] When my seals leaked after installation, I traced the problem to forgetting to clean the sealing surface on the camshaft before replacing the seal.   I was used to Japanese engines which have a positive stop on the seal to ensure it always goes in the same depth.  The Volvo seals don't have this stop, so I put it in just a little off from where the old one was. The old location was smooth due to the presence of the old seal. The new location had some build up which ruined the seal in no time.  I pulled it apart, cleaned the camshaft with fine emory cloth and replaced the seal. No more leak. [Response 4: Kerry Schutt]  Be sure to clean the seating surfaces on the engine real well where the seals go. Most of my time doing the job was spent cleaning those areas. I used small cotton rags and lacquer thinner and kept rubbing until it was all shiney metal. I didn't want any leaks after I was done.  [Response 5: Alan Carlo] So now I gently turn the seal onto the shaft  when assembling to prevent this. Then check the installation with a mirror and flashlight, all around.  Be sure to pre-lube the seal surface where it contacts the shaft before assembly. A Volvo tech told me to use white lithium grease to fill the small recess of the shaft contact area. Also do not hammer the seal in as the jolts can dislodge the spring causing a leak.  [Response 6: Dick Riess] Volvo even went so far as to advise a wait of 20 minutes to make certain they were in ok as they can flip the seal lip. I use some Vaseline on my seal lips and use an old seal backwards to tap on to insert new seal. Donít drive new seal all the way in either. Would clean the crank surface with some of that 3M Scotchbrite of or a strip of fine emory papers like they use to polish cranks. [Editorís note: use the less abrasive Scotchbrite blue].  [Response 7: Ivan K] To prevent the seal spring from getting out of position during installation, pack the area around it with grease.  [Response 8:]  When punting the cam oil seal, I always put a bit of red RTV/Permatex on these seals between the cylinder head and bearing cap for insurance...  [Editor's Note: See Cam Seal Replacement]  Also use sealant on the valve cover gasket, where it has a sharp bend around the front bearing cap.

[Technical Tip from Volvo TSB 21121 Oct 93]  New seal designs are now used for camshaft and intermediate shafts starting in Oct 93.  The seals (p/n 6842273-2) are more compact and use a special version of the seal installation tool p/n 9995025.  Lubricate the seal and press it onto the shaft using the tool.  To ensure that it sits correctly, it must be pressed in for at least 30 seconds.  If pressed for a shorter period, it may creep back out.  Remove the tool carefully to avoid damage to the seal lip or spring.

Crank Seal Leaks After Installation.

[Problem:] I could kick myself! I just checked my front main crank seal I replaced a week ago! After running the car for a short bit, I noticed leakage at the bottom of the crank housing! Ahhhhgg! I know when I put the seal in it was flush to the housing and felt even all the way around! I have heard you should seat them deeper when replacing one - but it looked good and I did not have the proper seal tool to do the job, plus I afraid to seat it to deep and get a leak that way. I used a giant 3/4 socket to seat it in the past. But this time I didn't have it around! I bet I didn't seat it far enough or messed up the spring! [Suggestions:] If it leaks after installation, you probably flipped your seal lip; I have done it more than once. [More:] Something I did on mine when I replaced it was coat it thoroughly with petroleum jelly. I had been warned that the seal can be messed up by installing it "dry". Also, are you sure it's straight? If it is cocked at an angle, it will leak. Also, You may have popped out the spring! If you pounded the seal the spring can pop out. Check it! If you didn't buy an original seal, check the rotation mark. They make seals for both rotation directions. [Eventual solution:] Spring had popped out.

Leaking Rear Seal and Replacement Tips.  [Query:] I had my Volvo to the dealer today. They told me that there is a slight leak in the rear main oil seal and that it would cost between $700 and $1000 to fix. I only plan on having the car another year or so. Is it really necessary to have this fixed?   I never noticed any oil leak and I'm not losing more than .2 qt oil between oil changes (3000 miles.)  Is it okay just to keep an eye on the oil level and then fix if absolutely needed?

Diagnostics: Check Flame Trap Function.
[Response: Gene Stevens]  Before replacing the rear seal, have you made absolutely sure that the crankcase vent system isn't plugged? The N/A engine uses a flame trap (which doesn't belong on the Turbo, but that doesn't stop some guys from installing one anyway) and when it gets blocked causes excessive crankcase pressure, pushing oil out wherever it wants to go.  I've heard of new replacements seals being pushed out of the bore from the same pressure that caused the old one to leak. Curing the pressure may slow or stop the leak.
[Response: Ted]  If the seal is seeping keep close tabs on it. Make sure that the flame trap is clear and working properly. If the seal is leaking because of wear this will not be a factor, but if it is leaking because of crankcase pressure the excess pressure can actually push the seal right out of the back of the engine, creating a large leak.

Replacement Tips

[Response: John Sargent ]  The reason it is so expensive to replace the rear main seal is that the transmission must be removed to access the rear of the crankshaft.  To fix it yourself, you pull the transmission and clutch/pressure plate assembly or the respective auto transmission parts. The rear main seal is pressed into a seal housing. You remove this and press in a new seal. Then you reinstall the seal housing with a new gasket. The seal and gasket are less than $20. When you reinstall the seal over the crankshaft flange, you have to be sure that you don't push one edge of the seal lip over. [Response: Randy]  I'm assuming you have a transmission jack. I purchased an inexpensive one from Harbor Freight because several people here at the BrickBoard advised me NOT to try to use a floor jack. It was good advice. It really takes some shaking and push/pulling to remove and install the transmission. My experience is with the 240 but you'll have the same type of situation with the 740. On the 240's it is a very tight fit between the transmission and the sheetmetal in the area of the starter.
While you have it out it is a good time to replace the front seal on the transmission (readily accessable once removed) as well as the rear seal and output shaft bushing if the bushing hasn't been replaced yet (you'll need the gasket between the transmission and the rear housing if you replace the bushing). There are various other seals on the transmission that can be replaced at this time- look for fluid leaks.
The transmission cooling lines may not come off as you plan (rust and corrosion) and you may need to cut those lines to remove the transmission. You can use a high quality hose and clamps to save the cost of purchasing new lines.
Clean up the crankshaft with carb cleaner of something similiar to remove any build up before installing the new mainseal. I packed the back of mine with grease and liberally greased the crankshaft. Don't try to start it straight on when installing on the crank or you might cause the lip of the seal to push out and the spring might come out of place. It would be a bummer to have a brand new rear seal not do its job because the spring was dislodged.

Cam Seal Replacement.  [Query: ] I have identified an oil leak on my 740 as a blown front cam seal and I'm preparing to replace it. Any tips I might benefit from? [Response 1: Don Foster] Very often, the cam seal is the first to leak when you have excessive crankcase pressure -- so it's good you're going after that, too. Don't forget to check and clean the small vacuum line from the flame trap to the intake manifold. And when you're done, perform the "jiggle" test with the oil cap.   Replacing the cam seal is straightforward. It's held in by the first bearing cap, and I prefer to replace it by removing the bearing cap. Of course, this means pulling the valve cover -- so be prepared with a new gasket.   Yes, the seal MUST be prelubed with motor oil, as well as the cam surface.  I just replaced the cam seal on a B21 engine -- almost identical to your B230. I use an air impact wrench to spin the bolt off the cam pulley. [Editor's Note: Better to use a Volvo tool called a cam sprocket "counterhold" to secure this sprocket.  See below under Damaged Cam Gear While Changing Seal.]  Obviously, I first highlight all the timing marks with white crayon.   Upon reassembly, I torque the bolt to 37 lb-ft.
    Incidentally, I replaced the seal by only removing the top pulley. First I set the engine to TDC. Then the tensioner was pulled back, and I used a small clamp to lock the belt to the intermediate shaft pulley (on a 240, that's important -- on a 740, not important) -- but still, you want the belt to stay in position. I also stuffed something down the passenger's side of the belt to prevent it from disengaging from the crank pulley. [Tip from Bill Gantt: I found that if you set the belt in place on crank & auxiliary shaft & use a small spring type clamp to hold them in place it helps until you release the tension pulley.]
    Once the seal was replaced and the cam pulley reinstalled, I looped the timing belt back over the pulley, carefully observing the timing marks. I reset the belt tensioner.   Worked great.  It's good you're replacing the seal -- excess oil can leak onto the water pump and cause the top "mushroom" seal to leak -- then you'll have more headaches.
[Response 2: Ozzie] you should probably just spend the extra money and replace all three front seals while you have the timing belt off. the only trick i found to replacing the seals was to use a can opener, the triangle tipped kind, to get the seal out...when you put the new ones in cover them in oil and make sure you buy them from a Volvo dealer...I got the wrong crankshaft seal, and lost mad oil. and I had to take everything back off and put the right one in...it took me 2.5 hours to replace all the seals, timing belt, and belts.
[Response 3: Zippy]  The latest seal installer for the cam and intermediate shaft seals is nylon
and steel and I don't see how anyone can successfully install the Volvo seals without it.  Some replace the seals at every 50,000 service, we do it every 100,000 or sooner if required. (which it rarely is)

Damaged Cam Gear While Changing Seal. [Problem:] While removing the camshaft sprocket (for a seal replacement) I put several small nicks in its teeth. I used a chain vise-grip with grippy rubber stuff in-between the sprocket and the chain. The chain cut through the rubber, hence the nicked sprocket.
[Diagnosis:] Why why why did you do that (sorry)? I always used to use a 17mm box wrench, tap the end with a hammer, and depend on the timing belt to hold the gear still. This slowly turns the motor over, but no problem, just move the wrench again. Or, you can use regular vise-grips to grab the non-rubbing part of the camshaft through cloth. You can try to find a used sprocket at a wrecking yard.
[Response 2: Paul Grimshaw]  To remove the cam gear (to install the seal on the camshaft), you will need another special tool called a counter-hold.  In addition, the timing belt tensioner makes refitting difficult [while the timing belt is in place.]  The last thing that you would want to do is wedge the cam gear back onto the cam as you run the risk of damaging the flange. [Response 2: Zippy]  Slack off the tensioner.

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