Smoke between shifts
 

I did a search before posting this thread and found some of the answers I was looking for, but not all.

Scenario- Just noticed today that the car is smoking between shifts under normal acceleration (5lbs of boost or less). It also smokes when downshifting to a stop, but it has always done this. No smoke while cruising or coasting to a stop.

I know the main factors of this, overly rich, Rings, valve seals or turbo and possibly crank case pressure. Rings and valve seals have less than 5k on them and were professionaly installed. Turbo has under one hundred miles, it was jsut rebuilt by Turbo and Import in Blaine.

The turbo had smoke coming from the exhaust housing before the rebuild. It did not smoke through the exhaust but from the outside of the housing itself, which I thought was unusual, so I brought it in to be checked out. They said it did not seem bad, but did show signs of normal wear, either way they put new seals in it and said it should be good. It no longer smokes under the hood, but now its out the exhaust.

How to diagnose:

Rings- Compression test
Turbo- oil in intake or IC piping near turbo
Rich- I have an AEM wideband, but not sure what exactly to look for. Could it be overly rich do to the weather?
Valve seals- ??
Crank case pressure- ??

My main guess right now is either Turbo was rebuilt improperly or too rich, just wanted some 3rd party input.

Re: Smoke between shifts
 

Where or who rebuilt the turbo?

Re: Smoke between shifts
 

You can also do a leakdown test and that will determine if it's your valves or you piston rings. Have you considered replacing your pcv valve? Orilies has OEM PCV valves for $6, don't get the super cheap ones they sell for any vehicle because they fail all the time.

Re: Smoke between shifts
 

It was rebuilt by Diesel and Import in Blaine


I didnt know the PCV valve could go bad, but I will replace it for $6.

Re: Smoke between shifts
 

Just make sure you get an oem one and not the cheap one they sell for $3. You will probably have to have one ordered but it shouldn't take long, autozone doesn't have the oem one so go to orilleys. Here is the link if you have a 1g, you have to order it but they probably have them in their warehouse, http://www.oreillyauto.com/site/c/de...2180&ppt=C0023

Re: Smoke between shifts
 

Could be crank case pressure, do you have any breathers or PCVs that pull vacuum on the engine? Too much crank case pressure while boosting at decent RPMs can cause the exhaust to suck oil past the turbo seal ring as soon as you close the throttle.

Re: Smoke between shifts
 

I dont know what you mean by pcv's pulling vacuum. How does that happen?

Re: Smoke between shifts
 

^ Having the hose from the side of the valve cover routed to the pre-turbo intake pipe so it's actively sucking air out of the crankcase would be an example.

Re: Smoke between shifts
 

Here read this, http://www.dsmtuners.com/forums/arti...cv-system.html

Re: Smoke between shifts
 

brought the turbo back to the shop because it there was soot in the intercooler pipe and the turbo seemed to have developed some play, but the shop said they dont think there is anything wrong with it and that the soot in the intercooler pipe could not have come from the turbo. Seems like they dont know what they're talking about, am I wrong??

If its not the turbo, what would be the next thing in line to check? As far as PCV, i have a small filter on the passenger side one and I removed the one on the backside, so it vent right into the engine bay. Anything else I can do to relieve or eliminate crank case pressure?

Re: Smoke between shifts
 

A compression test won't show a oil control ring issue, are you getting oil up into the cylinders?
Have you tried running the pcv system back into the intake? This is why I prefer catch-cans with good devided chambers, keeps the oil mostly out of the intake, but also keeps the vacuum system operational.