Billowy smoke on/after decel.

decamun

New Member
Joined
May 28, 2015
Messages
1
Location
Seattle
Hi all, I'm wondering if someone can tell me what's wrong with my turbo. I am running the stock CT-26 on my '88 7M-GTE MKIII, at around 8 psi. It still pulls and spools just fine, but on decel, I get extremely thick blue-grayish smoke clouds for a few seconds. I think oil is getting sucked into the intake through the bypass lines when air is flowing backwards through the turbo, so it only happens on idle just after decel, when pressure reverses.

Upon inspection of piping, it looks like there's a bit of oil going through the intercooler, but not reaching all the way up to the intake manifold. However, there's also quite a bit of oil on the compressor side of the turbo. A small amount of pooling on the housing outside the compressor, and the compressor is very discolored. The oil on the compressor side was what set off alarm bells for me. There wasn't much shaft play, though, and is seemed to spin without much resistance. (I'm pretty inexperienced. It was possible to spin the compressor wheel with one hand easily, but there was definitely enough resistance to feel it; it wasnt "feather light".)

I also recently changed and flushed the oil 600 or so miles ago, and this problem started 100 or so miles ago. I didn't prime the turbo or anything when I changed the oil. Stupid mistake. Maybe that could have caused the problem.

Does anybody more knowledgable than me have an idea what going on with my turbo?

Also, how likely is the turbo to fail further? I'm reluctant to spend lots of $$$ on this if I can get away with just topping up the oil, and thinking of limping until I can upgrade to something nicer.

Thanks in advance!
 
Last edited:

GC89

BoostRodeo
Authorized Seller
Contributor
Joined
Jun 13, 2007
Messages
1,037
Location
Spokane, WA
Turbo seals are shot, on decel there is a sharp vacuum condition which pulls oil into the compressor side and through the ic>tb.

Time for a rebuild