Compression test results, one low cylinder...

[Highlex]

My 7mgte has been burning oil, its the worst when the motor is hot and or the turbo is boosting. It doesn't smoke that much on cold start up, just a little.

I removed the charge pipes and checked for oil, nothing, I removed oxygen sensor behind turbo and checked downpipe for oil residue and also nothing, so turbo should be fine.

The car has a slight mis-fire at idle, also has a ticking sound on cold start up that sounds like a loud valve. every couple seconds you can hear it put-put-put, pulled spark plugs and they all look good, no signs of coolant.

Compression test results

#1 - 180
#2 - 182
#3 - 179
#4 - 130
#5 - 178
#6 - 178

cylinder #4 is way lower than the others, I added a tablespoon of engine oil and checked the number again with it wet, and it went up to 150.

What are my options from this point out, I plan to do a leakdown test and determine if its the rings for sure or could be something valve related?

Right now there is some ATF soaking in cylinder #4.........

Opinions?

 

[Another MkIII]

I would definitely move forward with the leak down test before making any assumptions. In any case though, at a minimum you are looking at all the labor to change the head gasket or more depending on what it turns out to be.

-AM3

 

[suprarx7nut]

When I do "wet tests" I add roughly 2 tablespoons of oil, maybe even 3. I'm not sure if 1 is enough to coat the walls reliably.

A valve could cause a subtle drop in pressure like that. I wouldn't guess rings at this point since you saw little change with the wet test.

Until you do a leak down test it's all guesswork.

 

[Highlex]

Ill do a leak down test and report back, thanks!

 

[hvyman]

If your burning oil rings are more suspect.

Unless you happen to have a bad sealing valve and leaking valve stem seal.