I had avery bad oil leak last March 2007 and ended up being the front crank seal. I had it replaced at a very respectable garage that has Subaru trained tecs. This May (2008) it happened again and I could not get it into that same garage so I took it to another garage, again with a Subaru trained tech. This time I had him replace the crank and cam seals and he had to replace the timing belt because it was oil soaked.

 

Well this weekend it just did it again and with very little milage since the last repair. I've got an apointment next Monday with the last garage I went to. He said it might be the PVC valve causing excessive crancase pressure and poping the seal out. Also there is a slight wobble of the crank pulley and he said he has seen alot worse than that amount wobble so he was not concerned by it. (he said the pulley groove that slides on the key pin on the crankshaft gets worn and that causes the wobble)

 

My OB has 143K on it and runs great otherwise. Anyone have any thoughth on what might be causing the seal(s) popping out before I give the OK to fix it again? All I know is something is not right. Thanks

Has the PVC valve ever been changed? I have read that it can cause issues with excessive pressure in the engine causing the engine to both "use" oil and blow seals......the PVC valve is cheap and easy to change, plus it should only help with performance.

check the PCV system for sure.

 

use Subaru seals only, i had a Fel-Pro seal do the same thing last summer. i've had 39 out of 40 Fel-Pro seals do just fine, but one didn't seat well.

 

the crank seal is installed int he oil pump, if that's compromised at all then a new seal will never seat right. i doubt this is the issue though as it would have happened after a seal replacement...not prior to.

 

they are right to replace the timing belt, the brand new belt i installed last summer on my friends car that began leaking only last 10,000 miles tops because of being oil soaked. his was non-interference so not a big deal, i replaced it. but yours is an interference engine, if that belt breaks your engine is toast.

 

that wobbling crank pulley is common, but it's hard for us to say much about it without seeing it. could be bad, could be tolerable, could be fine.

maybe the oil pump o-ring is leaking?

 

the crank wobble was the symptom before my crank pulley failure. mine was caused by improper torque on the bolt holding it on. even if the key way is slightly boogered, i would think the pulley would still spin true unless the bolt was loose.

 

it's just what happened to me. hopefully not you.

The screws on the back of the oil pump come loose fairly often. When this happens all the oil pressure pushes out the front crank seal. Some people replace the seal several times before discovering this. The oil pump needs to come out to tighten up and loctite the screws in to fix this. You'll need to replace the oring on the pump and reseal it to the block with sealant.

The screws on the back of the oil pump come loose fairly often. [...]

Yes, on both the 2.2L and 2.5L -- see http://www.motor.com/MAGAZINE/Pdfs/092001_08.pdf .

maybe the oil pump o-ring is leaking?

 

 

I agree with this one....and the screws arent a bad idea either.

Thanks for the help! It is now in the garage and my mechanic just called with an update. He said the crank seal had poped out. I checked the PVC valve this weekend and it seemd to function properly, but I think he may double check that. He said he wants to check out some more lines to see if he can find the cause. BTW he did use all Subaru seals when he replaced the crank and cam seals 2000 miles ago.

 

If the internal oil pump screws are lose would that cause the crank seal to pop out? I mentioned that to him but he said he would like to investigate othere areas first.

[...]If the internal oil pump screws are lose would that cause the crank seal to pop out? I mentioned that to him but he said he would like to investigate othere areas first.

See http://www.babcox.com/editorial/ic/ic70228.htm . Under "REPLACEMENT PROCEDURES", step 8 says:

>>Before you reassemble, there is one more step. Check and tighten the screws for the oil pump cover. These screws come loose and allow oil pressure into the crankseal cavity, which can push the crankseal out. This pressure loss also can cause the lifters to be a little noisy, which may be the initial clue that something is wrong in this area, beside the obvious oil leaks. <<

Further info, from Subaru (EndWrench):

http://endwrench.com/images/pdfs/TBeltEWWin05.pdf

See page 12, bottom, left.

Thanks for all the help! What my mechanic discovered was that two of the oil pump screws were out about 3/4 turn. He fixed that but he is not convinced that that was the problem. He cleaned as best he could the crancase ventilation system because he said it was dirty. Even after he finished he said there was still positive ventilation (air blowing out) out the oil dip stick (he said it should be negative). So I don't know, I guess I we will just keep an eye on it.

As long as in addition to dealing with the loose screws the mechanic properly resealed the oil pump, that should be okay. Having positive crankcase pressure means that either your engine has excessive blowby (combustion gases getting past the piston rings), or the PCV isn't functioning correctly yet (perhaps it's still somewhat "gunked up").