Mystery HUGE Oil Leak

dmechnic · Post by **dmechnic** » 13 Aug 2021, 02:18

Hoping you guys can help...the patient is my '04 V70 R AWD auto trans and its leaking 1 quart every 200-300 miles. It seems to be coming from above the transfer case as it is completely covered with pools of oil in the top recesses of the casting. The bottom of the trans also a mess as well as the entire driver side to the back bumper. I've had it apart (took out transfer case) and sprayed it down with brake cleaner to try to locate the leak. After idling for over an hour with intermittent & sustained revs for around 5-10 min there were no signs of a leak anywhere. Reassembled and a short drive produced the same multi-drip mess on my driveway. Also, the turbo and firewall did not have signs of oil when I started.

During reassemble turbo oil return seals replaced, rear exhaust cam seal replaced, rear intake cam seal solid. Head gasket was replaced a year ago and the leak started slow about a month or two after. The PCV is around a year old & works (negative pressure glove test at idle).

Any clue to where this amount of oil would be coming from? If the head gasket were bad I'd expect smoky exhaust and coolant loss as well but have neither. Suspecting the rear main seal but not sure. There is a space where the flywheel is exposed and it's kind of above the transfer case where it mounts to the trans. If the RMS is bad and dumping out could it spitting out of there? There does not seem to be anything coming out of the small weep hole at the bottom of the trans housing where it meets the block. I'm at a loss and don't have any $$$ to spend taking it to someone (got hosed last year on the head work...long story).

darylrobert · Post by **darylrobert** » 13 Aug 2021, 03:24

shorten your test drive. you could also try a dye in the oil because i know they can be very difficult to distinguish. I recently had to re-do my turbo oil return pipe because i messed the o ring up the first time, my transfer case was also covered in oil but. Have you checked the rear camshaft oil seals?

Post by **abscate** » 13 Aug 2021, 05:41

And the front camshaft oil seals too.

I took two years to track down a leak from the turbo oil return line into the block. If only I had read and acted on the first post made after I posted it.

dmechnic · Post by **dmechnic** » 13 Aug 2021, 05:59

Front seals done with timing belt less than a year ago. Turbo oil return line seals were intact but I did replace them with no change.

The test drive was about 1.5 miles each way and shut off in between.

nickbw898 · Post by **nickbw898** » 13 Aug 2021, 08:36

It's a fiddly job but I would replace the turbo oil return line seal. These things reputedly leak from almost day one. MY01 at almost 200,000 miles has no leaks except a very small one there and I replaced it 5 years ago.

Post by **jonesg** » 13 Aug 2021, 15:38

Another vote for turbo oil cooling return pipe. Re-did mine 3 times before getting it right. Royal pain those 2 top bolts.

Also check the copper washers/rings on the oil feed line banjo bolts at the turbo.
Don't re-use copper washers without annealing them with propane torch or get new ones.

Post by **SuperHerman** » 13 Aug 2021, 16:58

Cam cover? Anything you attached to the cam cover/block during the HG change is where I would start looking. Rear cam seals are also suspect.

Post by **RickHaleParker** » 14 Aug 2021, 00:01

Power wash the oil off. Add some tracer dye to the oil. Run the engine and watch for the tracer dye with a Ultraviolet (UV) light. Trace the dye back to the leak.

dmechnic · Post by **dmechnic** » 14 Aug 2021, 08:52

SuperHerman wrote: ↑13 Aug 2021, 16:58 Cam cover? Anything you attached to the cam cover/block during the HG change is where I would start looking. Rear cam seals are also suspect.

The HG job was done at “Swedish Car Specialists” here in Schaumburg as part of an exhaust bolt extraction (sheared off). Long story, had a “ticking” at startup that would go away after 5 min, thought it was possible valve issue so took it to a known Volvo guy. I got hosed. $6500 (he wanted $7500 but since he quote $3k-4k he felt bad) for 40 hrs of labor to get the head out and put back at $150/hr. Even better, car wasn’t reassembled correctly. Left out the hub bearing seal on the right axle, didn’t reconnect the turbo vacuum lines right (wrong location and one left unconnected), and I won’t even try to describe the liquid tape job on the ignition coil wires.

Sounds like I need to go back, get the transfer case out AGAIN, respray everything down with brake cleaner, reassemble, add dye, drive, disassemble a third time, and play hide & seek with the UV light. Well, when I put the transfer case back in for the test drive I’m leaving out the top bolt for sure…not struggling w that damn thing anymore than needed.

Post by **jonesg** » 14 Aug 2021, 09:15

You have the benefit of familiarity, it gets quantifiable faster to tear down each time.
I did mine without pulling the transfer case, it probably would have been faster if I had pulled it in the first place.