Volvo 850 T5-R Oil leak at high RPM

Ram · Post by **Ram** » 12 Jan 2018, 07:12

Sorry for the long wait - apparently I went into hibernation.

I did the compressiontest today, I i'd say the numbers look promising:
1. Cylinder: 165 PSI
2. Cylinder: 165 PSI
3. Cylinder: 165 PSI
4. Cylinder: 150 PSI
5. Cylinder: 150 PSI

This was the dry test. My mechanic friends had never heard of the wet test, and since the numbers weren't lower than 140PSI we decided not to.
The leak from underneath the engine is still extremely difficult to locate, so I'm contemplating dropping the oil pan, in order to change all seals, oil cooler hoses and properly clean the crankcase ventilation ports.

Ras

Post by **scot850** » 12 Jan 2018, 15:55

Wet test is to eliminate if the issue is worn or broken piston rings or bad valves. You do the dry test first and then do the test again with a little oil added to each cylinder. The oil will prevent compression getting lost past the piston rings, and if the readings stay low on one cylinder, then it is a sign the valves in that cylinder are bad.

Neil.

Post by **jtp** » 12 Jan 2018, 22:18

I’d do a PCV job on there ASAP

Post by **wizechatmgr** » 12 Jan 2018, 22:22

I'd go with Scot850's recommendation first. If there is excessive blowby then it can cause the same symptoms. Many folks have replaced the PCV system just to find no improvement - because it isn't the issue.

That said, if it hasn't been done recently then I'd definitely keep it in the running for potential sources of issue.

Ram · Post by **Ram** » 14 Jan 2018, 03:05

So you suggest I do the wet test as well?

My theory is that the PCV ports on the block are clogged, because I got oil in the intake hose.

Post by **wizechatmgr** » 14 Jan 2018, 03:50

There are three reasons you can get oil into the intake...

1. Turbo compressor oil seal is toast
2. Excessive blowby from piston rings creating more pressure than PCV system can handle
3. PCV system needs to be replaced.

Testing 1 is as easy as removing the turbo compressor to intercooler hose and looking for an excess of oil. If you see oil, don't worry yet, unless #2 & #3 appears to not be an issue.

Testing 2 can be done with a wet cylinder test vs a dry cylinder compression test - it isn't as good as a leak down test but it should suffice.

Testing 3 is a case of verifying there are no other issues with hoses being clogged, etc, and noticing crankcase pressure rather than vac.

Post by **rspi** » 15 Jan 2018, 12:22

Ram · Post by **Ram** » 19 Jan 2018, 10:57

Quick update:

Got the car on a lift today and removed the oil pan - more trouble than I thought it would be.
However, there seem to be a fair amount of burnt oil in the pan which I will clean out tomorrow. But the lower PCV port was about 25% clogged, where the block meets the pan (no pictures, sorry). In my opinion, this wouldn't be enough to create that much pressure in the crankcase.
Tomorrow I will remove the rest of the PCV system to see if anything else i clogged and provide some pictures.

Could the oil cooler lines be clogged and therefore increasing the pressure?

- Ras

Post by **scot850** » 19 Jan 2018, 14:59

Can't say I have ever heard of the cooler lines being an issue other than leaking with age. Does your car have the oil cooler thermostat under and slightly forward of the crank pulley? These can fail if you do, but never having had that issue not sure if it fails open or closed.

Neil

Ram · Post by **Ram** » 21 Jan 2018, 11:59

Okay got the rest done today, and here's some pictures:

: PCV port from the block looks clear enough, but I did scrape a lot of burnt oil out.

: PCV port to the pan.

: The oil pan itself - more dirty than I expected.

: The top port has clearly leaked oil.

: Then I discovered this: PCV elbow on the side of the manifold was not connected.

: PCV Box: Now it gets even more wierd. Why is the oil white? No loss of coolant.

: PCV connection: And it goes on.

: PTC nipple... And on.

However, with all this done, the Lamdba light in the dashboard turns on. Tried to reset it, but it return instantly.
I did the glove test - rubber glove on the oil filler, and it inflated, still...
However, the car does not seem to smoke as much, in ilde, as it did before.
I'm at a total loss, I have NO idea what is causing pressure in the crankcase, or why the old PCV system had white oil in it.

Bonus question:
These brake pads were on my front brakes. Brake rotor was a 320mm, while the carrier was from a Volvo V70 2nd generation. I'm quite sure the caliper is from an 850 (compared with other pictures), but the new pads I ordered specifically for 850 does not fit (look at 2nd picture).

: Old brake pads.

Volvo 850 T5-R Oil leak at high RPM

Re: Volvo 850 T5-R Oil leak at high RPM