Uhoh, Not Piston Rings, Please!?

[joemathews]

I noticed in some heavy traffic toward the end of a recent road trip that there were small puffs of blueish smoke coming out my exhaust when I revved in neutral or started to take off in gear. I didn't notice a continuous cloud while driving, like you'd often see with a head gasket. I am almost certain it is burning oil. It's not from the turbo, as far as I can tell, because I am still getting full boost and the T25 has no shaft play at all.

I think the problem might be that I overfilled the car with oil a bit at my last oil change. I'm not sure exactly how it happened, but I guess I didnt' check the oil level enough, and added maybe 1/3 of a quart above the fill line. Could the extra oil in the system be burning off because the oil pressure is too great? Or are my piston rings failing because I raised boost from stock levels over the past few months ?

Should I change the oil again before I drive 10 hours back home?

[1stGenRocks]

1/3 over shouldnt be a problem. most cars can go at least a quart over before you have engine damage. hell we had a civic that they put in 4 quarts over and its is still ok. they clogged up the cat, fouled the plugs fouled the o2 sensors etc but no engine damage. not sure what your problem is but 1/3 a quart of oil over shouldnt do much

[joemathews]

I suppose the turbo seals could be leaking without there being shaf play...

But I just took a look at it again and revved the engine a bit, and there was no smoke this time. However, the engine wasn't completely warmed up, and the turbo hadn't been spooling. Would bad rings cause smoke all the time, or only on a warm or loaded engine? The fact that there WAS smoke and there still COULD BE smoke still troubles me, however.

Any other insights or suggestions on things to check would be appreciated .

[EclipseRST]

when you boost does your dip stick slide out a little/a lot? that is a good sign of piston ring wear/failure. other than that the only thing i can think of is valve seals, cause if the turbo doesnt have any play in the shaft i'm almost certain it wont leak. so my 2 thoughts on this are either your valve seals are bad or your piston rings are bad. do a compression/leakdown test, this will also determine whether or not your rings are bad so we can eliminate atleast 1 of the 2.

[kjewer1]

It's almost never the rings when the car is smoking. I've never personaly seen that turn out to be the cause. Even on motors with almost 200k miles that get raced regularly. That being said, I would focus on the turbo and the valve seals. If it does it most when you start it after sitting over night, or for a few hours at least, its probably the valve seals. A bad turbo will typically smoke all the time once it really goes. It is possible to smoke through the turbo with no extra shaft play. In fact its common on garretts getting too much oil pressure. You could try swapping to a head oil feed and see if that fixes it. Bad PCVs can also cause smoking, but its too early for me to try to figure out why and explain it.

I guess my point is there are a lot of possible causes, and rings are the least of your worries.

[joemathews]

Okay, that is a relief. I wasn't too keen on taking the engine apart anytime soon, so hopefully the rings are ok.

Jake, my dipstick never slides around, so that sign isn't there. Is there another way to test the turbo seals other than shaft play?

Kevin, I also read about the bad PCV causing smoke, so I will look into that more. I'll do a compression test later today and post results; maybe that will shed some light on things.

Thanks for the responses, guys.

[1stGenRocks]

its probably valve seals. the easiest way to be sure your piston rings are good is to do a compression test. buy a tester at autozone ($25) test each cylinder and then put a squirt of oil in each cylinder and check them again. i forget what the numbers should be but the bigger the difference between the dry and wet readings the worse condition your rings are in

[kjewer1]

Its hard to get a good wet test with dished pistons though, most of it just puddles in the piston dish.