So I finally installed my home brewed turbo set up a few weeks ago and I'm now getting a noticeable amount of smoke out of my exhaust mostly between shifts and on decel/coasting periods. It's white with a blueish tint and smells like oil. The car holds boost fine, drives really smooth, has 110k miles and didn't smoke before the install so I don't think it's an engine problem but I haven't done a compression or leakdown yet to test rings/valve seats.

The turbo is a freshly rebuilt Sr20 T25 turbo running 6 psi. I'm using a 3an oil feed off of a sandwich plate adapter and seeing about 25psi oil pressure at idle and between 55-60 when cruising. This is from my Innovate oil pressure gauge reading off of the same sandwich adapter. Running a 10an oil return that doesn't run uphill or seem to have any kinks in it, brand new OEM 323 GTX PCV valve, a cheap ebay catch can from the pcv to intake manifold, and then a breather on the other side of the valve cover, 2.5" Begi seperated gasses downpipe to the 2.5" catless Isis exhaust. 6an coolant feed and return lines.

Has anyone seen similar smoking issues or have any clues as to what could be the cause? I thought it was improper crankcase ventilation at first but even with breathers on each side of the valve cover it was smoking. I'm leaning towards a problem with one of the seals in the turbo but wanted to ask the experts first. I attached a video of it smoking between shifts/me driving so you can get an idea of when it smokes.

TL;DR Why is my car smoking so much between shifts?

 

Pop rivet restrictor. Do it.

 

Smoke on decel sounds like dead rings. Try this. Rev it up, then let it coast down pulling vacuum. Then step on it. Puff of smoke means bad sealing rings

Check intake piping for oil

 

Oil line restrictor.

 

I know you said the oil return was ok but make sure. I had many smoke issues caused by kink or not going down hill.