Tripl7

After searching a few hours and not coming up with much of a straight answer on this problem I am turning to the experts(you know who you are).
Ok so heres the skinny. 176k assuming never freshened up, never rebuilt, only mod done by PO was APE chips and a crappy 6 piece exhaust job.

I just pulled the intake and am fearing the worst as tons of oil is everywhere it shouldn't be. Compression numbers as follows 140 - 130 - 135 - 140. Open the throttle and oil runs out. Oil is currently pooled ontop of the valves. Intercooler had maybe 2-4 oz oil inside before flushing. Pre-cooler hardpipe very minimal film. J-boot has oil pooling right where the AOS ties into it so I know where the oil is coming from. I would have done a leakdown test if my gauges on it were not broken, I will be addressing that soon enough.

Knowing these engines have a high oil consumption rate and what I have infront of me, I will be taking a crankcase pressure reading when I get something rigged up but for now, with this many miles and age, am I looking at rings being shot or no?

Those of you that have catch cans, was this problem similar to what you had going on before installation?
I read in a thread that there is a media inside the AOS, although I have one I pulled apart and it was lacking such a thing.

I plan on cleaning all oil out of everywhere it is and monitoring the issue slowly, any other suggestions on approaching this? I want to get to the bottom of this so I know to make a call on a rebuild or not...Thanks

Sapientoni

The common practice these days is to check "leak down" with 100 PSI air. That tells you the general condition of the rings, valves, valve seats. You just can't wear these things out because of the silicon in the aluminum. That is if you keep oil in them. You might consider putting valve seals on and that can be done without opening up the crankcase. Also check the thrust bearing by indicating the crank movement. I have an '87 with 50,000 miles the owner let run dry of coolant and it never indicated "hot" but died as he entered his driveway. Compression was 75-50-25-25. From my race mechanic days I've learned todays piston rings anneal when overheated and lose tension. I've not opened it up, but would like to sell it. My engine is NA.

E-man930

Your turbo could be the oil slinger... You need to do leakdown and report back.

JacRyann

Compression looks decent so I think your rings are fine. I had massive oil build-up on the back of my intake-valves at 120k-miles. Turned out the turbo was the culprit.

On another 951 with lots of oil in intake, it was bad rebuild job by another shop and most of the valve-stem seals popped off. I always machine grooves into the end of the valve-guides now to keep them in place.

Tripl7

I thought the same shortly after I got the car, but being such an amount of oil in the j-boot where the AOS ties in, I imagine its all coming from the AOS.

Now...I hooked up the leakdown gauges not for a reading, but for a leaking HG that was thought to be bad by the PO. I do know the valves seal very well, no pressure into the intake or exhaust, all air came out through the AOS which is why I'm suspecting rings.

How would I isolate the turbo being the source, if it was? I think a catch can will be going on shortly in order to see if the amount is reduced in the intake tract or not.

Thats no dice, coolant sensors need coolant in order to tell an accurate temp, air isn't much of a heat conductor as liquid. I ran into the same thing on a truck I bought years ago, good thing it was all cast iron and more forgiving than alloy, I got lucky in that case.

kev951

Valve guides and stem seals if they have "never" been touched. They are way past their prime.... plus once the head is off, time for aos seals, front end reaseal, cycling valve , inspecting bores, etc