I'm getting puffs all the way to large clouds of blue smoke from the tail pipe only on decel (and especially on downshifts). I'm thinking that the rings might not be seated (Hellfire) as I haven't put more than 500-600 miles on it since the rebuild. Also thinking it could possibly be a bad turbo seal / crankcase EVAC problem. Its getting kind of embarrasing. Any ideas?

 

well its DEF oil...check the seals on the turbo

 

If its only decel i would say valve seals.

 

I checked the turbine for shaft play, and their is some small movement from side-to-side and no axial movement. (I'm not sure what is normal). The turbine is defintely not hitting the housing and the turbo is only 500-600 miles old. Is their a procedure for checking the seals?

I thought about that too, but wouldn't it smoke on start-up or acceleration as well, I guess I just don't know why valve seals would leak only on deceleration.

 

They only leak on decel because thats the only time that you are drawing negative pressure on them. In boost you would be pressurizing the crankcase. On startup some of them leak and some do not. But i have seen many that leak only in vacuume.

 

Blue smoke is oil. It can be caused by too much fuel, washing the sides of the cylinder walls and allowing oil to slip through.

If it is due to deceleration, then the common culprit is valve seals. If it occurs during acceleration, then it's usually rings or excessive fuel.

If it's 100% of the time, then it could be anything, but very likely serious.

 

For ****s and giggles how do you have your Cranks case ventilated?

 

I'm running the stock "formed" hose that steps up to a 5/8 hose that is then connected to the intake side of the turbo. I originally had an oil/water seperator inline but took it out to allow more vacuum. (The line runs uphill so no oil has made it into the intake.)

 

how many pounds of oil pressure does your engine make, how much does your turbo get and do you have a restrictor in the feed line? maybe too much supply pressure? just a thought

 

I get regular good oil pressure in the engine; I'm running a -3an feed line from the port above the oil filter and a -10an drain down to the oil pan. I remember reading somewhere that -3an was small enough to where you wouldn't need a restrictor.

 

have you figured out what this is yet? I have the exact same problem however I have no pull on my PCV system its just a filter on the valve covers.