It's Dead, Jim ('01 3.0i)

[aureliusmax]

Originally Posted by nahvkolaj

I’ll check them again with some oil squirted in. The engine did seem to run smooth when I started it last week, no misfires.

this is either your taking the compression test wrong (not fully insert oring / thread from compression hose) because no ignition on two cylinders would register as misfire and you would feel large engine shakes.

do the compression test again, don't get distracted by the other 9 people here telling you to pour spoonfuls of oil and sugar inside your cylinder it's doing nothing but waste time in your diagnose. do the job properly, move forwards.

[white_335i]

Originally Posted by aureliusmax

this is either your taking the compression test wrong (not fully insert oring / thread from compression hose) because no ignition on two cylinders would register as misfire and you would feel large engine shakes.

do the compression test again, don't get distracted by the other 9 people here telling you to pour spoonfuls of oil and sugar inside your cylinder it's doing nothing but waste time in your diagnose. do the job properly, move forwards.

I am curious why you say that putting some oil in the cylinders doesn't help? Fuel tends to wash away the oil that is on the cylinder walls and sometimes doesn't help seal the rings. I've ran into this issue with my car, but like I said curious to know your thoughts.

[aureliusmax]

Originally Posted by white_335i

I am curious why you say that putting some oil in the cylinders doesn't help? Fuel tends to wash away the oil that is on the cylinder walls and sometimes doesn't help seal the rings. I've ran into this issue with my car, but like I said curious to know your thoughts.

that's not how it works. compression tests are to be performed with the fuel and ignition disabled. so if you're washing away your cylinder with fuel when doing this test first of all you're doing it wrong.

because the troubleshooting process for adding oil into the cylinder only makes sense if you first register a 150 psi and you can determine that your rings are clogged / worn out if you see an improvement of 190psi. minimum pressure for fuel ignition is 140psi. it's basically an indicator if you should plan for an engine rebuild or try to add an oil additive like MMO or autorx and check again compression at the next oil change to track for improvement.

when there's 30psi in a cylinder oil added is not going to tell you anything useful.

[nahvkolaj]

I retried a compression test on 2 and 4. Still sub-30 psi.



I did a poor man’s leak down test on #2 and #4. Pulled the 1-way valve out of one of the compression tester adapters and shot 40psi compressed air in. Definitely air coming out of the exhaust side on cylinder 2, but air coming out the intake side on 4. Yes they were at TDC. Upon further investigation of #4 with a bore scope, there’s a bunch of crap (looks like flaked carbon buildup) on the valves and in the intake runners. Cylinder 3, below, is clean by comparison on the seating surface. I would suspect #2 is like this as well on the exhaust side.


I ran some fogging oil for men and compressed air through #2 and #4 with the intake and then exhaust valves cracked open. #2 got up to 140psi on the gauge. Okay.

I gave everyone a couple shots of oil from the little oil can, and re-ran the compression test:

1: 200
2: 220
3: 210
4: 240
5: 215
6: 225

At this point I’m planning to patch up the cooling system and run the engine to check for gas.

[aureliusmax]

Originally Posted by nahvkolaj

I retried a compression test on 2 and 4. Still sub-30 psi.



I did a poor man’s leak down test on #2 and #4. Pulled the 1-way valve out of one of the compression tester adapters and shot 40psi compressed air in. Definitely air coming out of the exhaust side on cylinder 2, but air coming out the intake side on 4. Yes they were at TDC. Upon further investigation of #4 with a bore scope, there’s a bunch of crap (looks like flaked carbon buildup) on the valves and in the intake runners. Cylinder 3, below, is clean by comparison on the seating surface. I would suspect #2 is like this as well on the exhaust side.


I ran some fogging oil for men and compressed air through #2 and #4 with the intake and then exhaust valves cracked open. #2 got up to 140psi on the gauge. Okay.

I gave everyone a couple shots of oil from the little oil can, and re-ran the compression test:

1: 200
2: 220
3: 210
4: 240
5: 215
6: 225

At this point I’m planning to patch up the cooling system and run the engine to check for gas.

Not sure exactly how to explain your results but seems like adding the oil was sealing the valve seats ?
I feel like you should take the head off and get it pressure tested and rebuilt.

[nahvkolaj]

Originally Posted by aureliusmax

Not sure exactly how to explain your results but seems like adding the oil was sealing the valve seats ?
I feel like you should take the head off and get it pressure tested and rebuilt.

Yeah maybe the oil is covering up a problem. But, again, this is my first go at troubleshooting this kind of thing.

Just cleaning the valve seat surface as much as I was able to seemed to take care of a majority of the problem, and explains the audibly smooth running I heard before I tore in.

[Effduration]

I re-skimmed this thread from beginning...it's a bit crazy

-Overheat and possible warped head. Car towed home
-Multiple coolant leaks, including from recently installed hard coolant pipes.
-Low compression on 2 cylinders magically goes away with a little oil.

Since the car has not been sitting long, and hasn't been driven in a cold climate, and hasn't had trouble starting (no mention of it) I doubt it is bore wash on cylinders 2 & 4 although its a remote possibility..

A head scratcher for sure, let's see if compression in #2 & #4 remains.

[nahvkolaj]

Originally Posted by Effduration

I re-skimmed this thread from beginning...it's a bit crazy

-Overheat and possible warped head. Car towed home
-Multiple coolant leaks, including from recently installed hard coolant pipes.
-Low compression on 2 cylinders magically goes away with a little oil.

Since the car has not been sitting long, and hasn't been driven in a cold climate, and hasn't had trouble starting (no mention of it) I doubt it is bore wash on cylinders 2 & 4 although its a remote possibility..

A head scratcher for sure, let's see if compression in #2 & #4 remains.

Yeah it’s been a roller coaster for sure. Thinking the engine is toast, it’s maybe not, the head’s probably toast, maybe it’s not…

It’s never been hard to start. Used to get a misfire every once in a while but new coils and plugs fixed that maybe 1,000 miles ago. Compression tests were done with the intake off so no cylinder washing would have happened. The car is sitting outside but the intake ports are plugged with paper towels and the little air swirler ports are plugged with vacuum caps.

The only thing I can think of is that flaky carbon buildup I saw got on the valves and borked the seal pretty bad. Best case is that’s the only issue, but I wouldn’t be surprised if the valves end up having more problems than just being dirty. I reeeeeeeally would like to get away with not pulling the head off this thing, but we’ll see.

I really appreciate all the support and suggestions so far, guys. Thank you!

[X5chemist]

Wow! What kind of camera did you use? Picture detail is nice!

Carbon flakes may come off with FI cleaner.

If it has not run for a while, some valves are open or not seated properly.

[nahvkolaj]

Originally Posted by X5chemist

Wow! What kind of camera did you use? Picture detail is nice!

Carbon flakes may come off with FI cleaner.

If it has not run for a while, some valves are open or not seated properly.

I have the Ames 2.7”, $90 at HF. Had to take a pic of the screen with my phone.

The engine last ran on the 23rd or 24th of December, so not even a month yet.