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

[nahvkolaj]

Well the leak is at the heater pipe. The intake had a bit of dripping oil in the runners but the CCV was replaced not too long ago. I scoped a couple cylinders and they were normal looking, a bit of flaking carbon on the pistons.

Compression test results:
1: 182 psi
2: <30 psi
3: 180 psi
4: <30 psi
5: 180 psi
6: 168 psi

From sticking my crappy bore scope down there I can’t tell anything obviously wrong with pistons 2 and 4.

[aureliusmax]

Originally Posted by nahvkolaj

Well the leak is at the heater pipe. The intake had a bit of dripping oil in the runners but the CCV was replaced not too long ago. I scoped a couple cylinders and they were normal looking, a bit of flaking carbon on the pistons.

Compression test results:
1: 182 psi
2: <30 psi
3: 180 psi
4: <30 psi
5: 180 psi
6: 168 psi

From sticking my crappy bore scope down there I can’t tell anything obviously wrong with pistons 2 and 4.

Doesn't really matter at this point. Your compression losses are either: due to warped valves and they don't seal and air either goes to the intake or exhaust side. Or, breaks in the head gasket where air can exit into the coolant system.

In order to determine which, you need to get a leak-down testing tool. Compressed air at 10-20 lbs is sent to your cylinder while at TDC and if you see bubbling in the coolant tank that's a failed head gasket. If all the air rushes through exhaust or intake, your engine head valves no good.

If just the head gasket, go ahead and replace it.

If bad valves, Buy a known good used engine from wrecker, take the head off, install onto your existing block. Run compression test again, more likely than not going to solve the issue the most inexpensive and quick solution.

[andrewwynn]

Before replacing head or gasket, did you put any oil in the two leaky cylinders? I've read it's common to put a tsp of oil in the cylinder for the compression test but then +1 on the advice above.

[nahvkolaj]

Another tool I get to add to my box it seems. Hopefully I’ll run that down this week. Fingers crossed for a head gasket but there was almost nothing on 2 and 4, it sounded like how kicking over a bike with no rings left feels.

Regardless of head issues, is there any reason I should be concerned about the block? Seems the head is what sees the most extreme temps.

This has been an interesting exercise in troubleshooting. I’ve not had to do this on a 4-stroke engine before (let alone a car).

[aureliusmax]

Originally Posted by nahvkolaj

Another tool I get to add to my box it seems. Hopefully I’ll run that down this week. Fingers crossed for a head gasket but there was almost nothing on 2 and 4, it sounded like how kicking over a bike with no rings left feels.

Regardless of head issues, is there any reason I should be concerned about the block? Seems the head is what sees the most extreme temps.

This has been an interesting exercise in troubleshooting. I’ve not had to do this on a 4-stroke engine before (let alone a car).

when you take the engine head off, you can use a flat-edge and feeler gauge to measure for block warpage and the maximum variance will be listed in the engine specifications. it usually doesn't happen as it's most often the head that warps.

[white_335i]

Originally Posted by nahvkolaj

Another tool I get to add to my box it seems. Hopefully I’ll run that down this week. Fingers crossed for a head gasket but there was almost nothing on 2 and 4, it sounded like how kicking over a bike with no rings left feels.

Regardless of head issues, is there any reason I should be concerned about the block? Seems the head is what sees the most extreme temps.

This has been an interesting exercise in troubleshooting. I’ve not had to do this on a 4-stroke engine before (let alone a car).

If like you said, cylinders 2 and 4 have 30, you should have noticed the engine misfiring when you started the car. In your earlier post, I thought you said the engine ran smooth.

I would agree with the other post above, add a tea spoon of oil in cylinders 2 and 4 and check for compression again. I had noticed this in my 330i a few years ago where I did a compression test on a healthy engine and I remember cylinder 1 had 30 psi. I added a spoon of oil to all the cylinders and it helped.

[nahvkolaj]

Originally Posted by white_335i

If like you said, cylinders 2 and 4 have 30, you should have noticed the engine misfiring when you started the car. In your earlier post, I thought you said the engine ran smooth.

I would agree with the other post above, add a tea spoon of oil in cylinders 2 and 4 and check for compression again. I had noticed this in my 330i a few years ago where I did a compression test on a healthy engine and I remember cylinder 1 had 30 psi. I added a spoon of oil to all the cylinders and it helped.

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.

[white_335i]

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.

Do you have an air compressor? Can you do a leak down test?

[nahvkolaj]

Originally Posted by white_335i

Do you have an air compressor? Can you do a leak down test?

I do have an air compressor but no leak down kit. It’s easy enough to retry the compression test with a squirt of oil in 2 and 4 that I’ll do that first.

Edit: I did try multiple runs on cylinders 2 and 4, so it shouldn’t be a gauge seating issue. Hard to believe that the rings could be so dry that they don’t seal worth a damn anymore but testing again is not a huge endeavor.

[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.