So I've been having an issue with intermittent smoke at idle. It will usually take 2-5 minutes of idling before smoke starts rolling out of the exhaust. I have never notice the smoke at any other time.

I'm 100% sure its the turbo...its a precision 6262.




So my current crankcase ventilation setup is just an open front port (~.5") and a non-operational pcv (no vacuum applied from the intake manifold). When measuring the vacuum/pressure, the gauge will flicker around 0, maybe a touch on the positive side.




Using the same setup with the pcv open and drawing air out of the valve cover, the gauge still flickers around 0, but a little bit on the vacuum side.


I decide to close the front breather port, and draw through the pcv valve into the manifold. Eventually it created about 7-8 inhg of vacuum, and I stopped there becuase of some motor noise (sounded like a faint chirping) that I did not recognize. Maybe it was too much vacuum, I'm not sure. At what point does the vacuum draw too much and keep oil from going where it needs to go?





All this time, the car really did not change smoking wise from one setup to another. Letting the intake manifold draw air through the pcv might have helped a little bit, the the turbo continued to leak oil through the turbine seal.

I am going to see what it does under boost, as I'm curious to see how bad I might be building up pressure.



But yeah I am lost on the smoking issue, other than it being a year old precision. Return is a 5/8" ID with a smooth downhill path to the timing chain. I have a borg warner s360 that is replacing the precision, but would like to avoid any chance of oil backing up into the center section.

 

I say it's a bad turbo. For all Garrett and precision ball bearing turbos you must run a .035 restrictor for the oil feed and a .06 restrictor for all non ball bearing turbos. Also make sure you have a -10 straight and good oil return. I always say go with Garrett or Borg Warner and stay away from precision turbos. I have never seen a precision turbo last for more than 20,000+ miles. And I have persionaly have used Garrett ball bearing gt turbos for over 100,000 miles with no problems what so ever.