Smoke after boost/letting off throttle
 

I have a single turbo FD(6265 PT), the problem I'm having is whenever I go into boost or let off the throttle to change gears I get a bit of smoke out the exhaust(blue/black in color). It's not a ton but enough to see in the rear view... which is driving me crazy! It's been doing it for a while and after reading tons of threads I realized it was the turbo seal so I got the turbo rebuilt and its still doing it:scratch: I installed a catch can prior to the rebuild cause I know that sometimes it's crank case pressure issue but that hasn't helped either... Any help on this would be greatly appreciated.

I tried searching but only found ones that suggested the two things that I've already tried:confused:

If more info is needed I'll try my best as I'm new to rotaries and cars in general but I'm doing my best to learn.

Your turbo drain line might be to small or not flow the oil away fast enough.

It's a AN-3 I believe which is what precision recommends. After a lot of reading I think I'm going to try a 0.060 restrictor cause I know that my oil pressure is pretty high; my builder said it's 100+. Thanks for the response. Any other suggestions?

Yeah was talking about drain back to engine not feed line to turbo, do you not run oil pressure guage? restrictor may help.

yeah the drain is AN 4 I check today and no I don't have oil gauge yet... its on the list but I didn't want to buy anything until I got this turbo situation figured out. I ordered a restrictor today so we'll see in a week or so.

AN-4 is tiny for drain line, the hole out of the turbo body should be bigger than that. You need to make the drain as big as possible to allow oil to drain away as easy as possible as you need to remember feed in is under pressure but the drain has to rely on gravity to feed back to the sump. I personally run 3/4" ss tube on mine but have run AN-10 before on a Garrett T04Z and had issues with smoke on deceleration. Google oil drain line size man there's lots of info out there, AN-4 is way to small.

Cheers Brad

Crank case vent.

thanks I check into it.

and thanks Killa

Take the line off your oil neck. I know you have a catch can but just try this. I had the same issue and had a catch can. Ended up being a line to it was pinched.

sk8world - I tried what you did... it didn't work.

I did however put on a 0.065 restrictor on the turbo inlet and no smoke. Now I just have to set something up to ensure I'm getting enough oil to the turbo and not starving it.