2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

light smoke upon revving motor

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Old Jul 17, 2012 | 07:57 PM
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CA light smoke upon revving motor

Hello all, firstly, i have a 90 turbo...heres my situation:

when I rev the engine, during idle (in neutral) or when driving, there is a very faint smoke trail. Its almost un-noticable when driving, but when I am parked on the driveway for example and revving, it can be seen.

I did some research and on FC3SPro it says to test the oil control rings by reving to 4k and holding it for 15 seconds and if theyre bad smoke will pour out the exhaust, and I tried. There is smoke, but its very light, and not cloudys of smoke.

Also, I thought it might be coolant seals, but there are no bubbles when i pop the radiator cap, and the overflow tank doesnt fill up or anything, I dont burn through coolant either...

my question is, what else could be causing this slight smoke? Could it be a bad turbo? (its a stock s5 turbo) i notice it doesnt spin as freely as i thought it would. Theres no shaft play but i need to put pressure on it to spin it and it immediately stops when i release my finger. It really has me stumped and I dont want to do any damage to the motor anymore. Any suggestions or tips? Thanks.
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Old Jul 17, 2012 | 08:10 PM
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What color is the smoke? It might just be gas that hasnt burnt from running rich, could be oil...rx7s do burn oil
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Old Jul 17, 2012 | 08:41 PM
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Oil bro....... You got a rotary

Hybrid
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Old Jul 17, 2012 | 08:50 PM
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^ i agree.
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Old Jul 18, 2012 | 02:03 AM
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i should also mention i have the OMP blocked off and lines/injectors removed. would it still be burning enough oil to make a light mist of smoke? the color is really really light blue...mostly white? i took the turbo to intercooler pipe off and there was some oil coated in the hose and at the intercooler inlet, could that just be blowby? im just a bit paranoid.
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Old Jul 18, 2012 | 08:46 AM
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Its still going to burn oil with the gas when premixed. Unless the smoke is heavy i wouldnt be too worried, when its smoking like a banshee then.youre in trouble.

When my coolant seals went my car was smoking so bad it looked like i was doing a brakestand when i revved it up, it was horrible.
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Old Jul 18, 2012 | 01:12 PM
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oil smoke isn't normal you chuckleheads...


pull the TID and check the turbo for thrust play, if any then the turbo is likely the culprit. if not, remove the plugs and if they have a wet film of oil on them then the oil control seals inside the engine are going out.
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Old Jul 18, 2012 | 02:01 PM
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Well i thought an.engine that burns oil will have some smoke. I was wrong?
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Old Jul 18, 2012 | 02:07 PM
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the turbo should spin freely.
If it stops that is sign of a bad bearing,and oil is what lubes it.Bad bearing..oil seeps out into exhaust..smoke.
That is where you are going to find your problem.
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Old Jul 18, 2012 | 02:14 PM
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I have a similar issue. As said previously, mine is due to the turbo seals.
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Old Jul 18, 2012 | 06:29 PM
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From: Union City, CA
Originally Posted by RotaryEvolution
oil smoke isn't normal you chuckleheads...


pull the TID and check the turbo for thrust play, if any then the turbo is likely the culprit. if not, remove the plugs and if they have a wet film of oil on them then the oil control seals inside the engine are going out.
thank you for the tip, i will pull the plugs just to check. hopefully the oil control seals will not be the culprit.

Originally Posted by misterstyx69
the turbo should spin freely.
If it stops that is sign of a bad bearing,and oil is what lubes it.Bad bearing..oil seeps out into exhaust..smoke.
That is where you are going to find your problem.
yeah mine definitely does not spin freely. i have to apply a bit of force on the blades for it to move. im basically pushing the blades in order for them to spin. it still spools and holds boost though when driving around looks like its time for a BNR upgrade hahah
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Old Jul 18, 2012 | 07:29 PM
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From: Dinwiddie, Va
Sorry for the bad info, never owned a turbo.rotary or any turbo car for that matter, goodluck
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Old Jul 18, 2012 | 07:48 PM
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rotaries in general don't smoke unless they are having issues or premixing too much oil.

burning oil generally means carbon deposits, too much carbon= blown motor. there is always exceptions to this however, some cars that had really bad oil control seals had less carbon because the rotors were always saturated with oil
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