Ok I got my car going again after a minor head gasket replacement, but prior my car was smoking not alot but here and there. Keep in mind it was running pig rich prior to dyno as well. anyways i a mrunning a B20 vtec turbo motor presicion turbo 500whp, if i idle for a period of time then drive off it will smoke for just a bit and go away while crusing. now while just driving there is not smoke the times i see it is if i deccelerate on the highway and let the car slow down and tap the throttle i see alot of smoke. i also see smoke under boost but just for a bit as well any ideas im not sure if im just burning all the crap in the exhaust from running rich for so long. Leak down test show great across the board and compression as well.

 

some seem to this it is valve guides but i had the head check out when i pulled it off to replace the head gasket and it was perfect. maybe wash down in the cylynders from too much fuel

 

smoking on deceleration sounds like valve seals need to be replaced, also you could of washed the cylinders also form running the car too rich. you might want to check the oil seal on the turbo that can be bad also if you don't have some kind of pressure restrictor for the oil going from the engine to the top of the turbo.

 

I just got the Turbo back from precision they told me that my last turbo failed due to oil starvation and said not to run a restrictor, also if the valve guides were bad would that show up when they bench flowed and tested the Head?

 

valve seals not valve guides.

 

never replace a set on a b series motor the head have to come off to replace them i assume they do.

 

usually when a turbo car smokes on decel, something is wrong with the turbo....check your drain make sure it is angled properly and is the right size....rule of thumb is a 5/8, 1/2" minimum

 

Blown turbo seals.

 

The turbo is brand new Bro