Over the last year I have been constantly fighting oil leaks. My car is a 1990 945 Turbo with 185K miles and I have recently replaced the front main seal, the pan gasket and the valve cover gasket. Now it seems that lots of oil is leaking from around the oil filter area. I have not been able to exactly pinpoint the exact source. Is there anything around that area that is more prone to leaking oil? Also, I cleaned the crankcase ventilation tubes. Is there anything else that must be done along those lines that may help this problem?

Thank you in advance as always,

Anthony

Your oil leak is most likely the o-ring between the Oil Cooler Adapter and the block. There is also another o-ring at the filter end, but the block side always leaks first in my experience. It is not a bad job to replace. Do it at your next oil change. By the way, we own three 740Ts, and while all have had an oil leak at one time or another, there are no oil leaks off any of the three cars and the driveway and garage floor is clean under them.

You're on the right track, and Yes, there is a LOT in the oil filter area that can leak oil. (and they all probably are, bite the bullet and redo them all...)

Turbo drain pipe: gasket at top, o-ring at the bottom

Oil cooler lines: one copper crush washer each:

Oil filter assembly/arm whatever you want to call it: there's one oring about an inch from the filter, and another one where it meets the block, as well as a copper crush washer for the big ~30ish mm "bolt" holding it to the block.

About $20 in seals, and a messy messy evening under the car, but so worth it. (Not hard, just messy.)

If you want to finish the ventalation cleaning job, check out this link: I would try doing the job without removing the manifold first, to see if you can. (I was able to.) http://cc926945-a.nhaven1.in.home.com/oiltrap.html

Good luck!

-Paul Demeo

1990 780T

Thank you all very much for the valuable information. I think that I'll start with the oil cooler adaptor ring first and see what happens.

Regards,

Anthony