smoke diagnosis...

[Boosted19]

well it smokes badd. greay oil smoke. when ever i make boost. (i have a t25 so i can make boost when i rev it.) as soon as it makes boost is comes poring out. its a 95 tsi with 95k on it. any suggestions on what it is? the turbo? car still has power. idles great. doesnt smoke until boost. before when the exhaust manifold gasket was leaking oil was coming out of it. just little bubbles of it. (where it meets the head.) the outer bolt was loose. any ideas of what the problem is?

 

[MrBoxx]

Check the turbo for shaft play by removing the intake pipe and trying to wiggle the compressor wheel. Any in/out shaft play indicates a failing turbo which can cause smoke to erupt from the exhaust. Any significantly noticeable shaft play side to side or up and down also means the bearings and seals may be failing. Oil in the lower intercooler pipe is also a good indication.

Also, do a compression test and/or a leakdown test. These will help determine if the head gasket, piston rings, etc. are leaking.

 

[Boosted19]

well ill look at the turbo today. and maybe to a comp. test today. ill post up my results. i no they gotta be withing 20 % of each other.

 

[dieseltech]

When you burn oil it's usually blueish smoke, not grey. If it is indeed grey smoke it could indicate a restricted air filter. I don't think a boost leak would cause grey smoke, but on that im not 100%. Perhaps someone else could clear that part up.

 

[ChvyKc]

Definately sounds like the turbo is gone. On every T25 that I have seen running higher than stock boost it hasn't lasted very long. I think MrBoxx hit it on the head.

 

[MrBoxx]

When you burn oil it's usually blueish smoke, not grey. If it is indeed grey smoke it could indicate a restricted air filter. I don't think a boost leak would cause grey smoke, but on that im not 100%. Perhaps someone else could clear that part up.

In actuality, if you check the majority of blown turbo threads, the usual color of smoke from the exhaust is indeed grey/white. Most people think white smoke is ALWAYS coolant and oil burning is ALWAYS blue smoke, but some synthetic oils (Mobil1 comes to mind) burns whitish-gray, and if it were coolant burning, it would smell sweet like coolant. In the case of the turbo going bad, it's almost always oil getting dumped into either the intercooler pipes or directly into the O2 sensor housing, and it almost always produces white/gray smoke.

 

[Boosted19]

well did the comp. test and checked for shaft play... comp. was 150, 150, 148, 150. that is really good but the first time i did the test was 155, 150, 125, 150 so i did it again like 3 other times and the 150, 150, 148, 150 is what i got every other time. so i dont know if i let off to early or what. but i had all the plugs out, disconntected the coil pack, DID NOT disconnect the fuel injectors... I was doing it outside, running out of daylight and my hands were to freaking cold to pull the clips off. but i had the pedal to the floor, which i think shuts the injectors off during stratup on theses cars right? It was hard to feel for shaft play thus it being freezing out my fingers didnt work to well to fit into the tiny t25. there was some side to side but a tiny bit of in and out but barely any. i could only get my hand on the inlet side of the turbo. it was still on the car. im running stock boost on the car. its all stock but exhaust. the timing was off a tooth before. so i have done a t belt and WP about 2 weeks ago. (i dont drive the car right now no insurance) and the alternator is shot. it is over charging when i give it gas goes up to about 17-18 volts!!! i dont think those have anything to do with it just stating other problems just in case.
still think its the turbo? that was my first guess just want to make sure... oh and i have only 87octane in right now. i just bought the car off of my brother and he put it in by mistake. i dont think i get any blow by either my dipstick stays down in its home!

 

[Boosted19]

ok well update. the car smoked at idle a little yesterday. after i revved it up to do some more diagnosing. it started smoking a little at idle. i pulled the licp off and there was no oil. i pulled the down pipe off and looked inside for oil didnt really see any, just water it looked like. but the car didnt seem to smoke much with the DP off. maybe because there was so much black coming out. any ideas?

 

[Boosted19]

anyone???

 

[MrBoxx]

Please don't bump your threads.

If you have any in/out shaft play, there's a good possibility that your turbo may be failing.

 

[Boosted19]

sorry didnt mean to bump just trying to get some help!. did you read post 7 and 8? still sound like a turbo. it was hard to tell about the shaft play b/c i have the turbo on the car yet....

 

[papasapusc]

I have a similar problem. My car doesn't smoke at idle, but whenever I drive. I took of the intake, upper intercooler, and lower intercooler pipes and there was oil in all of them. Not too much, but little puddles in them. My turbo has no shaft play, from what I can tell, but I am thinking that my turbo seals may be bad. I just ordered a rebuild kit and I am going to try to rebuild it and see if that works. Do you think that this is a good approach or am I overlooking something. I will keep you posted whenever my rebuild kit comes in.

-Mike N.-
'91 GSX