Intermittent oil burning

[Frank Darcy]

I know this is a difficult question to answer, over the internet, without being able to look at the car, but I thought someone may have had a similiar experience. My 85 GN with 100k runs super clean but sometimes it will make a cloud of blue smoke. It seems to be under deceleration, however, I can drive at the same speed on the same road and the car won't do it again. I just changed the pcv valve but it did not correct the problem. The car doesn't smoke at all during acceleration. I was thinking it's the turbo. Any thoughts? Thks

 

[1QUICK85]

Does it smoke at all on start up after sitting for awhile? Valve seals?

 

[Frank Darcy]

It seems to smoke only when it's up to temp, under deceleration and if it is in smoking mode, it will smoke at idle. Really odd. It goes from running super clean to making a cloud that is very embarrassing.

 

[1QUICK85]

Your sure its blue and not white? Maybe a compression test would be a good place to start?

FWIW....when my turbo was burning oil it smoked white. I have read others that have had white smoke from the turbo blowing oil too.

 

[BRAD_PADGETT]

When my turbo died the car would intermitently blow white smoke like a crop duster. If this is the case run top engine cleaner after you replace the turbo. I chased down knock at low boost for two years before I figured it out. Carbon on the pistons. Brad

 

[HvyMtlV6]

I had a similar problem awhile back, my car would smoke here and there, whether if its idling or upon acceleration, but it would come and go. If your MAF pipe has the factory "S" hose hooked up to the oil filler tube on the valve cover, its probably sucking in oil as well. Pull the MAF pipe off, opened the throttle-body, shine a flashlight inside, you might find some oil residue on the turbo fins, thats what happened to me. Put an aftermarket valve breather on that might help, but eventually my turbo(turbo seals) just went one day while driving on the freeway an all I saw was in my rear view mirror was a big blueish like smoke covering the whole freeway - there are alot of factors that could contribute to your situation, good luck hope this helps you abit

 

[b4black]

With the throttle body before the turbo, the turbo sees vacuum when decelerating. This can suck the oil past the shaft seals. Hot Air turbos use a different seal than IC turbos.