Pistons rings? Valve seals? Or something else?

[SnprSlick]

Hello,
My car smokes at idle and shoots a plume of smoke on startup. As the car idles the smoke returns. It's oil the smoke is blue tinted.

My compression is
#1 160
#2 85
#3 160
#4 160

So I think it's safe to assume it is #2.

Could it be bent valves? I don't have access to a leakdown test anywhere near here so I'm gonna have to go ahead and pull the head and see. But I just wanted some opinions so I know what to look for.

The car doesn't idle rough and drives fine. It just smokes at idle...

 

[TurboAnything]

My car is doing the same thing and i assumed it was piston rings as i have had the head off and it looked good.

 

[delta448]

It's oil the smoke is blue tinted.

Could it be bent valves?

It's possible, you may be leaking oil from a damaged guide on a slightly bent valve(s). I'd be more inclinded to think that there's either a broken ringland on the piston, or the headgasket is leaking.
Check the edges of #2's piston well, and look for excessive scoring on the cylinder walls of #2. Check the head for corner to corner straightness with a precision straightedge and feeler gauges.

 

[SnprSlick]

Okay. I just did the test by myself. I had someone else do it last time. But this time i got:

160 160 180 180

When I did a wet test it went 180 across

Also. The car burns through oil like nobodies business.

 

[frankgbacoa]

Hello,
My car smokes at idle and shoots a plume of smoke on startup. As the car idles the smoke returns. It's oil the smoke is blue tinted.

My compression is
#1 160
#2 85
#3 160
#4 160

So I think it's safe to assume it is #2.

Could it be bent valves? I don't have access to a leakdown test anywhere near here so I'm gonna have to go ahead and pull the head and see. But I just wanted some opinions so I know what to look for.

The car doesn't idle rough and drives fine. It just smokes at idle...

dsm r known for smokin. i think you just need some new valve stem seals. if you can get some high performance ones it will save you some work at the long run. a bad head gasket or bad piston will make the compression a lot lower than your readings.

 

[delta448]

Okay. I just did the test by myself. I had someone else do it last time. But this time i got:

160 160 180 180

Those numbers are pretty good. What could you have done differently than the other guy? With almost 100psi difference, was that something a shop told you?

The car burns through oil like nobodies business.

I would start by checking the turbo for shaft play.

dsm r known for smokin. i think you just need some new valve stem seals. if you can get some high performance ones it will save you some work at the long run. a bad head gasket or bad piston will make the compression a lot lower than your readings.

I've seen 8.5:1 pistons with pretty nasty detonation damage at the edges still produce over 100psi on a compression test. After he checks the turbo, the valve stem seals would be my next recommendation, the turbo is just much easier to check first.

 

[SnprSlick]

The turbo does have shaft play. Nothing major no in and out. But I just changed to a 14b. The t25 had the same smoking and oil problem and it had no shaft play. I think the turbo is fine. As for the test previously. It was done on a warm engine by my cousins friend. I got a gauge of my own now that I can check with. I'm gonna do a warm test today