Smoking Problem Driving Me Crazy

[Jaywilliee22]

I have a 96 gs-t. The car is completley stock except for full exhaust and an air intake.It occasionally lets out a grey exhaust smoke. it is not a constent smoking issue only during shifting, deceleration, and sometimes at start up and idling. Am I gettin water in the cylinders? I have also noticed blue smoke during shifting at high rpm is this a sign of failing turbo seals? The car has sat for at least 2 years. I use synthetic oil, premium gas, and all fluid levels are to the "T"

 

[Jimmer307]

damn... i just posted like the same exact thing you did at the same time... weird ill keep an eye out on both threads to c who comes up with the answer first... sorry for wasting space... just thought it was interesting

 

[icekilla126]

do you have your bov recurculating??

 

[twicks69]

Well, it can be a few things; poor compression due to worn piston rings; worn out valve seals: blown turbo seals; and very poor tuning.

In this circumstance, I would lean towards valve seals or turbo seals depending on the type of wear the car has had; especially since it likely still has the stock T-25 turbo on it. You can pull off the exhaust manifold from the cylinder head and check for oil residue on the exhaust ports of the cylinder head --> Piston Rings or valve seals would be a likely culprit. To discern between those two, you can do a compression test on all four cylinders, and you can do a leak down test (by a professional) to see where the pressure loss is -- if any. It could also be a couple bent valves, but I think you would be seeing other driving issues, idle issues, etc. Usually toast valve seals will give you visible problems under decelleration, idle, startup, and load changes. The other side would be toast piston rings, which would show more problems under startup, and acceleration.

The turbo seals are fairly typical to fail on the T-25's especially if they have been overboosted during their life. This would cause a nice Spy Hunter-like smoke cloud behind you usually under acceleration. If the cylinder head exhaust ports are sooty, but not oily residue, you can disconnect the O2 housing and the downpipe from the turbo and check for oily residue or oil in your turbine housing, O2 housing or the downpipe. If there is oily residue in the exhaust system after the turbo, but no residue on the cylinder head exhaust ports, your turbo is likely suffering from blown bearing seals, requiring a rebuilt turbo, or a replacement turbo.

Also, poor tuning, or installation of an aftermarket blow off valve that is not recirculating into the intake pipe after the mass air flow sensor will cause rich conditions because it seeing unmetered air. You would need a properly tuned air/fuel controller (such as an S-AFC) to tune out the differences of running a BOV that is vented atmospherically. Even then, it is not a proper way to run the blow off valve as you still are running a Mass Air Flow system; to properly run the BOV vented atmospherically without affecting the vehicle's tune, you would need to run a Manifold Absolute Pressure (MAP-sensor) Sensor setup with the proper standalone or applicable piggy back controller. In this circumstance, I would have the recirculation tube still connected between the BOV outlet and into the Intake pipe.

If your BOV is stock, and is recirculated back into the intake pipe, I would be currently leaning toward valve seals, but it will be up to a professional to see under inspection of the problems.

Good luck with fixing your problems!

 

[No_Skillz]

And you can't smell carbon monoxide.

 

[twinscroller93]

Well, it can be a few things; poor compression due to worn piston rings; worn out valve seals: blown turbo seals; and very poor tuning.

In this circumstance, I would lean towards valve seals or turbo seals depending on the type of wear the car has had; especially since it likely still has the stock T-25 turbo on it. You can pull off the exhaust manifold from the cylinder head and check for oil residue on the exhaust ports of the cylinder head --> Piston Rings or valve seals would be a likely culprit. To discern between those two, you can do a compression test on all four cylinders, and you can do a leak down test (by a professional) to see where the pressure loss is -- if any. It could also be a couple bent valves, but I think you would be seeing other driving issues, idle issues, etc. Usually toast valve seals will give you visible problems under decelleration, idle, startup, and load changes. The other side would be toast piston rings, which would show more problems under startup, and acceleration.

The turbo seals are fairly typical to fail on the T-25's especially if they have been overboosted during their life. This would cause a nice Spy Hunter-like smoke cloud behind you usually under acceleration. If the cylinder head exhaust ports are sooty, but not oily residue, you can disconnect the O2 housing and the downpipe from the turbo and check for oily residue or oil in your turbine housing, O2 housing or the downpipe. If there is oily residue in the exhaust system after the turbo, but no residue on the cylinder head exhaust ports, your turbo is likely suffering from blown bearing seals, requiring a rebuilt turbo, or a replacement turbo.

Also, poor tuning, or installation of an aftermarket blow off valve that is not recirculating into the intake pipe after the mass air flow sensor will cause rich conditions because it seeing unmetered air. You would need a properly tuned air/fuel controller (such as an S-AFC) to tune out the differences of running a BOV that is vented atmospherically. Even then, it is not a proper way to run the blow off valve as you still are running a Mass Air Flow system; to properly run the BOV vented atmospherically without affecting the vehicle's tune, you would need to run a Manifold Absolute Pressure (MAP-sensor) Sensor setup with the proper standalone or applicable piggy back controller. In this circumstance, I would have the recirculation tube still connected between the BOV outlet and into the Intake pipe.

If your BOV is stock, and is recirculated back into the intake pipe, I would be currently leaning toward valve seals, but it will be up to a professional to see under inspection of the problems.

Good luck with fixing your problems!

I have very similar issue n I'll be more specific...it doesn't smoke at all when it's cold and only at an idle when it's really hot n u tap the throttle and when u get in 3rd gear or better n put it under full boost anything over 5500 rpm or so and the let off into vaccum it drops a rediculous oil cloud. I'm also experiencing high crank pressure and boost loss over 5500 rpm....drops to ten psi

 

[2fast2evo]

Low boost and oil pretty much means turbo seals as far as I would be concerned^ As for the OP's question, it's hard to say whether it would be turbo seals or valvetrain. If you want to check if it is turbo seals, just see how your cold side intercooler piping is looking as well. If it's all grimy with oil, to quote Jamie from Mythbusters, "there's your problem!" All else that was said above still applies. Just start checking things, try not to drive it too hard/too long at this point unless you have to.

 

[twicks69]

7 year thread revival. Geez.

 

[2fast2evo]

Newbie lesson learned: Also read the date on the FIRST post not just the last one