Smoking out the exhaust pipe

[drownthecity]

Okay, so I know there's a bunch of threads related to this. So the past few months my car had been smoking at idle, like at stop lights and at WOT. I replaced the valve seals and then it started smoking when letting off the throttle. It would also smoke at stop lights for a short time after getting off the interstate at idle.

I replaced the turbo with a used T25 I got off the classifieds here but it is still smoking but possibly not as much (or maybe that's just my wishful thinking..)

The only CEL I have is for my rear o2 sensor but that shouldn't make a difference I'd imagine.

Could it be rings? Or..?

 

[black97spyder]

Sounds like bad turbo seals leaking down into the exhaust. This would cause the CEL and make it smoke occasionally like you say

 

[DSM1G90]

I'm pointing at weak oil rings allowing oil to be pulled past the rings by the massive vacuum created when the throttle plate is closed when you let off the gas pedal, but can see the other opinion as well - both could be at fault for your oil burning issue.

 

[Dsmkauai]

Rule of thumb when buying a used turbo always have it rebuilt or do it yourself. Most t25's you find now a days will have plenty of miles on them and I wouldn't run one without a rebuild first.

 

[DSM1491]

I would check bottom end. I had a problem with my friends car bought it dor 2900 and everything seemed fine until the 2nd day. Car started smoking bad from the exhaust. I checked it out everything seemed fine until I took of the intake and the t25 had so much play it toughed the sides of the turbo....I had a spare one since I got a 16g. I ended up putting the turbo in my friends car and it didnt smike as much. The next day it it didnt smoke much but later that night she called me saying her car started turning off and had a wierd noise in the engine. I went to check it out chanes the spark plugs just in case that was the problem. The car turned on and I heard the noise it was making. Immediately turned it off and said it was rod nock. Towed it to my house took off the oil pan and found one rod was loose. Took the rod out and saw that it pretty much had no rod bearings and started eating part of the crank. Now we have to rebuild need new rods and crank. Check that just to be on the safe side.you can avoid spending all that money and use it on mods or something you needfor your car. Just thought this might help. Sorry for the long story haha dont wanna see anyone else go through that when it can be avoided

 

[drownthecity]

Rule of thumb when buying a used turbo always have it rebuilt or do it yourself. Most t25's you find now a days will have plenty of miles on them and I wouldn't run one without a rebuild first.

Any way you can check the seals without taking it apart yet?

 

[Bud92gsx]

Any way you can check the seals without taking it apart yet?

Check your ic piping for oil.That should help tell if the seals are blown.

Also color of smoke as well as smell of exhaust can help diagnose smoke.

 

[drownthecity]

Check your ic piping for oil.That should help tell if the seals are blown.

Also color of smoke as well as smell of exhaust can help diagnose smoke.

I'll have to check the IC pipes for oil. The smoke has a blue tiny to it so I know it's oil. And it literally smells like burnt nastiness.

 

[Bud92gsx]

Insert smoke color link (HERE) I'm on my phone I cannot link it.

 

[drownthecity]

Insert smoke color link (HERE) I'm on my phone I cannot link it.

I'm positive it's oil due to the color and smell.

 

[drownthecity]

Update - I checked out the intercooler piping for oil and all the pipes were bone dry. So I guess we can eliminate a bad turbo?

When replacing the valve stem seals, is there a chance they weren't seated down far enough or would the valve spring itself push it down?

 

[Bud92gsx]

The stem seals are a pain,and can cause smoke,more smoke when warm then cold.

I know this becasue me stem seals are shot in my current head.

 

[drownthecity]

The stem seals are a pain,and can cause smoke,more smoke when warm then cold.

I know this becasue me stem seals are shot in my current head.

I actually just replaced mine a few weeks ago. That's why I'm wondering - is it possible they aren't pushed down far enough?

 

[Bud92gsx]

Its more than possible..Honestly here's a way you can check.take the exhaust manifold off.And if u see oil in the exhaust ports,valve seals.

 

[TurboLaserRS]

Just a thought but, have you considered that your turbo isn't able to drain oil effectively? I've seen cars run at the track that the oil return couldn't keep up and the car would smoke after a pass. After some idling the smoke would stop.
Maybe make sure your oil drain line is doing its job.

 

[drownthecity]

Just a thought but, have you considered that your turbo isn't able to drain oil effectively? I've seen cars run at the track that the oil return couldn't keep up and the car would smoke after a pass. After some idling the smoke would stop.
Maybe make sure your oil drain line is doing its job.

Wouldn't that only be a problem if it only smoked during/after boosting hard? I could be wrong since I'm kind of new to turbo systems. So the oil would dump straight out the hot side of the turbo and burn out?

 

[drownthecity]

So I went back and reanalyzed some things while doing a little more research and have a few questions.
When I hit boost there is a decent amount of smoke pouring out my exhaust. Not a huge amount that I could see (it was also at night) but a buddy following me said it smoked pretty bad.

Would this eliminate the idea of bad valve seals?

Also, I'm probably going to check and see if the oil return line is clocked up or kinked at all. There is a bit of oil on the metal ring things around the line I've noticed when I looked at it earlier. I checked my old turbo I had on before I swapped it and I did not notice any fresh oil that was on the hot side outlet to the exhaust, although I've had it out of the car for about 3 days now. Would this be coated in oil if the return line was clogged or kinked?

 

[drownthecity]

Still haven't resolved this problem.

Could it possibly be to a not so quality PCV valve? When I installed it I made sure it was functioning and it seemed to be but this was about a year or so ago.

Also, are valve seals supposed to be lubed up with oil before putting them on? We replaced them pretty quickly due to time constraints and I suppose it's possible we ripped some of the seals? We used the seals available from DSM Graveyard.

 

[VisegripMech]

Sometimes the old seals leave a little crap behind, a little piece of the old seal stuck in the groove. If you did the seals with the head on the car, and didn't check each one with a dental pick, you may have a few new seals that er um, don't seal.

 

[drownthecity]

Another question..

I've noticed recently that no smoke is present at first start anymore. It's after about 1-2 minutes of idling you begin seeing small traces of oil. Maybe it isn't the valve seals after all??

 

[Jonesy75]

I'm thinking turbo seal... check the hotside turbine for oil maybe?

 

[drownthecity]

I'm thinking turbo seal... check the hotside turbine for oil maybe?

I replaced the turbo with a used T25 which looked in good condition. Didn't seem to have any axial shaft play. I checked the turbo that I took off originally for oil anywhere and it had a faint few drops coming from the compressor on the cold side. The hot side was just completely black but didn't seem to have any oily residue on it, given I checked it an hour or two after it was removed..

 

[Firsts tuner]

I just replaced a 14b that looked great on the cold side. No shaft play either. When I pulled the hot side off however I found carbon build up all over the wheel. The oil was leaking out of the weak seal whenever I boosted hard and then came off to stop. It didn't do when I first started it, usually it took a couple minutes to start smoking. Just cruising the smoke was almost unnoticed. Hope I helped out at least a little.

 

[drownthecity]

I just replaced a 14b that looked great on the cold side. No shaft play either. When I pulled the hot side off however I found carbon build up all over the wheel. The oil was leaking out of the weak seal whenever I boosted hard and then came off to stop. It didn't do when I first started it, usually it took a couple minutes to start smoking. Just cruising the smoke was almost unnoticed. Hope I helped out at least a little.

Hmm. Maybe I'll try sending one of my T25's to be rebuilt. I hate to have to shell out money for a turbo to be rebuilt when it doesn't need it.. But I guess it couldn't hurt? Anyone have anyone that rebuilds these things?

 

[JusMX141]

Okay, so I know there's a bunch of threads related to this.

...so you decided to start another? Weird.


Pretty safe to say it's not the turbo if you swapped it with another and the problem is still there. If the smoke suddenly appeared after a valve seal job, I think you're wasting your time looking anywhere else.