valve seals???

[quick85nat]

my 87 gn is running pretty well,i just have a smokeing issue,when i am on the gas it is fine but if i let off then gas it again it lets out a puff of blue smoke,its not all the time only when i let vac max out on the gauge then give it gas again,or if i cruising in 4th really low rpm almost idle doing like 40? it will smoke......im pretty sure its valve seals,not the turbo,or rings is there a better way to tell? i have taken the up pipe off and its pretty clean in there as far as oil is concerned

 

[TurboMonteSS]

I talked to Limit Engineering about a similar problem. Coasting down a hill in second gear pulling 24 inches of vacuum and the car would start to smoke, not all the time, but just sometimes. I had already changed the PCV valve (which could very well be your problem) and had done a compression test, which showed all well within limits. I had a head gasket let go a while ago and I had both gaskets replaced. Limit said that after that happens, quite often the seals will go in the turbo due to contamination. I just ordered another turbo to see if that cures the problem. Evidently the strong vacuum pulls the oil through the turbo seal. Good luck!

 

[REDS HOT AIR]

on 86-87 set-up there is no vacum in the turbo when off the throttle

on 84-85 set-up there is

you could plug off the line to the pcv valve for a few days and see if i clears up to eliminate that ..

 

[QUIP'6']

i always understood that if you smoke under deceleration it was the rings

 

[quick85nat]

it dosent smoke on decel,it smokes after you decel and get on it again

 

[TurboBuickGNX86]

samething happen to me when i thought it was the valve seals.... it turned out to be my 3 weeks old turbo... my guess is if u never opened up ur block or touched the heads... it is ur turbo