Boulder e30 in need of some troubleshooting

[clarkkey594]

oil on the spark plug could be from a leaking/bad condition valve cover gasket, which may result in the subsequent vacuum leak, causing the hesitation/miss, and the oil is being burned off, resulting in the smoke?

just thinking out loud here....

I like this logic. Give the compression test a try and post up the results and we can go from there.

[colorado_cabrio]

Either - recommend replacing part number M20 with part number M50 or greater.

ha, ns. If this wasn't a creaky old carbrio I'd jump on that s52 setup...

I'll grab a compression gauge today.

[Atreus]

so....what happened?

[colorado_cabrio]

I ended up ordering the compression gauge from amazon, it arrived thursday. I'm borrowing a battery charger (to keep the cranking amp equal across the tests) and I'll run the test today.

Lets hope the rain stays away long enough.

[monkeytaco]

either - recommend replacing part number m20 with part number m50 or greater.

+1

[colorado_cabrio]

Ok here's the update:


So the battery charger I was to borrow didn't work out; I should be able to get it tomorrow. So these were all run off the battery alone.

Ran the compression test

#1 Oil on Plug 135 PSI
#2 Oil on Plug 140 PSI
#3 Oil on Plug 145 PSI
#4 Oil on Plug 145 PSI
#5 Clean Plug 140 PSI
#6 Oil on Plug couldn't get any PSI reading.

I think #1&2 may be slightly higher on retest tomorrow (Just need to crank the ignition a sec or more to get a full reading)

Obviously #6 is weird...Is 0 even possible without a hole in the block? I pulled the tube out and re-seated it twice, but still got zero reading. So maybe the plug is having the same seating issue? Or maybe that cyl is fucked? Hoping retest tomorrow yields some result on #6...

Another note is that the end of the gauge that threads into the plug seats came out filthy on all cyls except #5... I mean it was covered with wet deposits, so clearly the PO wasn't keeping up on oil changes, I have what appears to be to be a substantial gunk problem.

Side note I'm planning on attending the CUSCC show tomorrow, but was planning on going in my 04 Audi S4 Avant (The imola one that you see around town). I suppose I could bring the e30 if anybody though a listen would give a strong opinion on next steps, plus you can see the beater in person.

Thanks again guys for all the insight!

cheers
Brent

[clarkkey594]

Was the engine warm when you did the test? That is quite strange that you got a reading of 0 PSI on that cylinder.

[colorado_cabrio]

Yeah I had the whole car up to operating temp before the test was done, but #6 was the last one i tested. I did some more searching and while zero is possible, it still seems unlikely to be totally flat in that one cyl but fine in all the others.

I'll try to retest this AM, but I do want to wash the avant for the show.

[colorado_cabrio]

Ok so re-ran test tonight, cylinder #1 moved up to 140, but #6 is still reading zero. From what I gather that leaves me a wide set of potential problems: Hole in block, ring damage, or failed head gasket.

Given the sudden onset, I think a hole in the block is unlikely. I can run a 'wet compression test' to test for ring seal damage, but I'll need to find some oil squiring do-hickey.

Any advice guys?

[Roland H]

Leakdown will tell you where you are losing compression.

[clarkkey594]

Knock on wood but if the motor is bad you can always just buy Roland's S52. :D

[colorado_cabrio]

Yeah, that s52 may be a serious option soon...be the ultimate sleeper (the body is a total beater).

I'd need somebody with a hoist to host the swap (even better than a t-belt party right?)

Are there two s52s floating around currently? I sent chubs a PM on his, but hadn't heard back. Does Roland have one aswell? Same guy? Or just an inside joke? ;-)

Gonna pull my valve cover tonight to look for damage there. But I'm beginning to think likely a true head gasket failure: How do I test for that (Leakdown I'd need to borrow or take to Cal) is bubbling in the radiator they telltale for HG failure?

Cheers
B

[iamsam]

Chubby Already sold his, Roland is a different dude.

[colorado_cabrio]

OHHH snap, I solved the riddle (the problem at least, not the root cause)

so I opened the valve cover and found this:
(sorry for crappy iPhone pic)



So the rocker on the driver side of cyl #6 isn't centered over the valve; it's shifted ~1" towards the rear of the car. So i scooted it back in place, buttoned up the engine and the car is back to itself. I'll run a compression again to see how that cyl stacks up later.

Now onto the root cause:
I know that the m20 is an interference engine, so maybe the timing belt stretched or slacked and the piston slapped that valve and knocked that rocker out of place?

Or is there another reason that a rocker might slip out of place? Do i need to do more than slide it back into place?

[iamsam]

WHOOOAAA I have never seen that happen before!!! ha ha ha!! Well congrats on finding the problem! No wonder there was no compression!!!