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Hello All,
Thanks in advance for your help with this...I'm pretty much grasping for straws at this point.
Purchased a 1994 940 Wagon recently - B230FD - with 156,000 miles - and noticed oil leaking from behind timing belt cover. Figured it was clogged flame trap, so when I had timing belt replaced at a local indie Volvo shop, I had mechanic replace the front seals and perform flame trap service.
Shortly thereafter I noticed oil leaking from behind timing belt cover again, so I brought car to a second indie Volvo shop figuring first guy screwed something up. Second shop replaced front seals again, cleaned flame trap again, and advised that first guy installed sub-standard seals which he advised was the cause of the leak. When I asked if the leaking seals might have been caused by some source of excessive crankcase pressure other than the flame trap (like maybe breather box) he said no and reiterated that it was from the first shops lousy seals.
So, I headed home last night from 2nd shop confident that I'd have a (relatively) leak-free car.
This morning I checked under the hood and lo and behold, it's leaking again - only maybe worse this time.
I pulled the engine oil dipstick to see if I could determine whether I possibly have bad rings (read that if I did, i'd have oil spraying out) but no spray. Also have never seen any smoke from tailpipe at any time - so haven't thought that I had any ring-type issues. Engine runs smooth and pulls strong.
So what do you guys think? Do I have an un-fixable lemon on my hands, or is this something that I can realistically get under control?
You folks are the best, BTW - I've been able to fix so many little things on this car and on a previous 1993 940 as well.
Hoping for a miracle from the generous Brickboard gods :-)
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Let me add a few other possibilties:
1. Don't take the mechanic's word that the breather box isn't clogged. Have you tested it? Another thing you can do is pull the oil dipstick with the engine idling after the car has been driven for at least 10 minutes. If it smokes you have a clog somewhere.
2. Throw away the flame trap screen. I have thrown it away on both my Volvo's with no repercussions.
3. Unless new, replace all the flame trap hoses and the hose that connects the breather box to the flame trap. The breather box hose and the flame trap to intake manifold hose tend to clog with gunk. Sometimes they seem clear, but are really not. Replace them! This is cheap insurance. They are very cheap.
I went through the same sort of thing with my 240. Have patience as you will find the problem. Good luck!
--
95 855 GLT Sportwagon 215k, 90 244 DL 300k - after 10 years has a new home
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I agree with Mr. Walker. Remove flame trap baffle. Not needed and maybe even adds to the problem IMHO. See here for further: http://www.pbase.com/stealthfti/pcv
That being said, def lightly snug up all the carrier bolts after a thorough douching of the region with a can of Brake Clean(cover belts with Paper towels 1st), just to rule it out. Also agree you should put a set of eyeballs on the Crankshaft/Cam themselves to see if scored/schmutzed, preventing good contact.
Solvable problem unless Crank/Cam scored severely(perhaps during prev r/r).
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hello
i had a leak up front in the same area.
i replaced the seal two times with the correct seal installer tool but still leaking.
next i pulled it apart and removed all the timing belt covers which is three pieces. most important the back one that covers the seal carrier then put everything back together without the timing belt covers = all three left off.
start engine and drive around
stop open hood and look for leak
find leak at seal carrier
top three bolts had somehow loosened up and thats where the oil was leaking.
could not tell with timing belt covers installed.
i just left the covers off.
good luck
Mike
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I never found a seal carrier without a loose mounting screw. Tiny screws, low torque and shrinking gaskets plus vibration all contribute. As a matter of fact one rear seal carrier mounting bolt came out, tumbled around the and shout out of the inspection plate. I now use service removable locktite on seal carriers, among many other other locations.
Another common leak is the valve cover, front and back corners if auto-RTV was not used, in the corners that is.
Tom
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Dear Brett175,
Hope you're well. I have a car with the same engine. This problem can be solved, and most likely for small money.
First, remove the black rubber flame trap hose - which goes from the side-arm on the black plastic flame trap housing to a brass nipple on the manifold - and inspect the hose.
If the hose is clogged, replace it. If the hose is clear, check the brass nipple on the top of the intake manifold, onto which the flame trap hose attaches.
The nipple unscrews from the manifold, using - if I recall correctly, a 10mm deep socket. If the nipple is clogged, clear it, using a drill bit of the same diameter as the hole, to ream-out carbon-rich sludge.
If these things do not help, I'd replace the flame trap. If you have small hands, you can do this without pulling the intake manifold. Be sure to get a replacement gasket, as the factory-original gasket will have hardened with age.
Be careful when cleaning the area around the gasket, as one does not want dirt falling into the oil pan. See the FAQs for the entire procedure.
Finally, if all this does not cure the leak - and I'd be very surprised if that's the case - inspect the camshaft. If the shaft was not cleaned before seal installation, dirt on the shaft's surface could keep the seals from doing their job.
It is also possible that the seal has been mis-installed - at an angle, backwards (with the spring facing towards the front of the engine), or rolled (with a seal lip bent under). None of these things should occur. It is simply not that hard to seat these seals.
Alternatively, if the camshaft was scored, and the seals installed right atop the damaged area, the seal may not be able to do its job. To correct this, the seal needs to be seated a tad deeper (1/16", for example), so that the seal's lips are on nice smooth metal. If the surface of the camshaft feels rough, it can be polished with a very, very fine paper (6,000 grit or higher). If you're not comfortable doing this, any engine rebuilder can polish-out any scratches. There's no need to pull the camshaft to do this.
Hope this helps.
Yours faithfully,
Spook
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Hello everyone and thanks for your quick responses! So far I have pulled the flame trap hose nipple from the intake manifold (11mm deep socket) and the tube definitely had sooty deposits which probably halved the internal diameter. Used drill bit to clear out deposits and re-connected. Hopefully this will do some good. While I was at it, I blew into the hose which connected to that nipple and didn't feel blockage, but maybe partial obstruction would still be sufficient to increase crankcase pressure?
Quick follow-up question: I attempted to pull up on the large flame trap hose and was able to slide it upwards from the oil separator box. Can I effectively pull the whole hose/flame trap apparatus up from between the intake manifold runners, and thereby replace the hoses that way? When I was pulling upward there was an audible "click", and the same click when pressing back down - similar to the sound when pulling and replacing spark-plug wires. Didn't want to attempt this maneuver without confirming with you guys out of fearI'd break something...
Thanks again and I'll keep you updated.
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Dear Brett175,
Hope you're well. The breather box is bolted to the engine block. Even if it were not so bolted, it will not fit between the manifold runners.
Clearing the manifold's brass nipple certainly helped.
The tube atop the breather box can be pulled upwards, between the intake manifold runners. The "click" might be the hose coming free from the nipple, atop the breather box. I doubt that hose is clogged, as it is about 1/2" (inside diameter).
The hose from the flame trap's sidearm to the manifold's brass nipple can be probed with a piece of soft wire, the tip of which wire has been blunted/rounded using sandpaper. If the wire hits an obstruction, use some brake cleaner to soften the sludge. If you can clear the hose, re-use it, until a factory-fresh replacement is available.
Hope this helps.
Yours faithfully,
Spook
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the job is straight forward.
leaks if there is no unreasonable crankcase pressure are being caused by either
debris left from the old seal and/or varnish built up in th4e seal way where it rides or a scoring on the cam shaft or cam shaft bearing such the new seal has been installed right over the scoring.
this analysis presumes the seal has been pressed in far enough.
sorry to tell you but the new seal has to come out and you ought to be there when it does to make sure with YOUR eyes the area where it rides is clean of all foreign matter, there is no scoring on the bearing or cam. make sure the installer lubricates both the inside and outside of the seal before its pressed in.
this is a ridiculously simple job. you might want to consider doing it yourself and save some money
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Update:
First, thank you to Spook, Walker, and all others for your help!
Source of leak turned out to be front crank cover gasket. Per second shop, first shop did in fact install poor seals in addition to shoddy workmanship with regard to failing to clean and burnish shafts prior to seal installation, such that seals were leaking in addition to the crank cover gasket when i brought car to 2nd shop. The crank cover gasket leak was difficult to spot until after installation of new seals which evidently increased pressure on crank cover gasket thereby producing heavy leak. Borought car back to second shop who replaced crank cover gasket free of charge.
So far so good - after a couple of days of driving, no leaks!
I would be hard pressed to ever visit the first shop again, but the second shop should be commended for their professionalism and for standing behind their word that they would fix the leak - even if it meant returning a second time for additional labor and materials - free of charge.
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