2001 V70 Oil Leak Back of Engine

altalake · Post by **altalake** » 09 Nov 2015, 10:42

2001 V70 T5 with 195,000km has a slow oil leak at the back of the engine, more pronounced on the passenger's side. The oil seems to be starting at the head gasket but there is no oil under pressure in the block or head near those places - only coolant and it is not leaking coolant. Neither coolant nor oil are contaminated. Vacuum test for PCV looks good. No oil visible around timing belt system. No oil under spark plug cover.
I thought the oil dripping onto the driveshaft could create a false impression of where it's leaking from because it could get thrown anywhere but, so far, it doesn't look like it is getting thrown off the driveshaft - not enough there. The seep only seems to be right at the head gasket but there is an area closer to the cam gears which is not visible. Timing belt and cams all look clean and I wiped them with a clean paper towel just to make sure. No oily residue.
I could live with it like this but it will probably get worse. Any other ideas what might be the cause or causes?

Post by **abscate** » 09 Nov 2015, 11:28

Not quite sure where we are on engine in that pic

Front of engine is on passenger side in North America
Left of engine to front of car
right of engine to rear of car.

altalake · Post by **altalake** » 09 Nov 2015, 14:23

The leak/seep/drip is most pronounced on the right side/front (closest to passenger in NA vehicle) corner of engine and also a lesser seep/drip closer to the turbo (right side closer to driver). There is no drip from the turbo itself.
Here's another photo - not my engine, just a screenshot from a YouTube video - which shows approximately where the seeps can be seen when looking back up from under the car.

mbreed · Post by **mbreed** » 10 Nov 2015, 12:16

Could just be spilled oil from an oil change.

altalake · Post by **altalake** » 10 Nov 2015, 13:46

Good point and I hope you're right but here's why that's probably not the case:
I did spill some oil (not very much) during a change in April and discovered the drip/seep in September and cleaned everything thoroughly and then the drip returned. After this my mechanic also cleaned everything much more thoroughly & replaced the oil supply pipe to the turbo - not absolutely sure if it was leaking but this was a relatively simple repair and would help to determine the source of the drip. Then he cleaned it again.
Although the overall volume of the spill so far is small (not showing up on the dipstick after 2,000km) it is obviously running down that part of the engine block, dousing the driveshaft bearing housing and accumulating on the splash pan.
There is also no evidence of spilled oil any higher up than the head gasket.
To me this seems too persistent to be from a small spill 6 months and 12,000km ago - but maybe not.
Incidentally, I'm pretty certain this is engine oil and not power steering fluid, just to rule that one out.

Post by **vtl** » 10 Nov 2015, 15:04

How did you check PCV and when it was replaced last time? And what exactly was replaced?

altalake · Post by **altalake** » 10 Nov 2015, 18:59

Nothing on PCV replaced that I know of. I'm the second owner and the original owner had some records of repairs but not that. I tested it with a home-made device just to determine that air was being sucked into the crankcase. Air volume decreased slightly at about 3,500 rpm which is about as high as I usually rev it.
Another possible factor is that this leak only happens when the engine is cold which could help to explain the small amount of oil.

Post by **vtl** » 10 Nov 2015, 19:23

Wife's 2002 V70 with N/A engine has a small trace of oil in valve cover area. PCV was fine, I still replaced it just in case. My theory is the chemical gasket gives up over years.

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altalake · Post by **altalake** » 10 Nov 2015, 22:05

Dry all around the valve cover on my car - at least parts I can see and reach. I've blotted all the way around with a clean paper towel and no oil residue at all. The seep only seems to start at the head gasket - although I'm hoping it starts somewhere else and just follows the seam to where it drips.

altalake · Post by **altalake** » 18 Nov 2015, 01:15

More R&D. I now know more things that are not the source of this leak. Pulled the timing covers off and am sure now that nothing is leaking past the front cam seals. Nothing leaking from the valve cover. I have been concentrating on the front/right corner of the engine because that's where most of the drip appears to come from although it might actually be starting further back and following the seam of the head gasket before it drips. Any more ideas?