Its a single T76 kit, stock motor, GTP 6.0 heads, hotcam. At first I saw the car was hooked up with all pass side valvecover ports blocked off except for one with a small breather like used on the lids with air tube line, all intake ports blocked off, and drivers side PCV port was ran to the air filter in front of the turbo.

It was driven under boost like that with stock injectors At idle it would smoke like CRAZY, and it didnt like to restart because the plugs were so oil soaked weird gray tint to them. At this point I was asked to tune it with the 60 injectors that were going in. 02s were FUBARed, and it didnt like to be started, ran fine once running though, so I knew it wasnt a tune thing it was some other issue, that when I pulled plugs, found oil, and for now am running an open loop tune because it kills O2s I temporarily hooked up stock PCV/line like ATI has their kit setup, and 98% of smoke went away and the last %2 may have been because it was 15 degrees outside

After all that oil consumption, wasnt very keen on having any lines pulling from in front of the turbo, so he tried what everyone here recoomend, ran all valve cover ports with 3/8 line to a catch can with breather. At idle you can see crank case vapors from the breather, which is normal, but now under WOT it smokes, which it didnt used to do before. He says it seems like its smoking more and more now. Made ok power 455 hp/460 tq, with smoke rolling out the tailpipes. It fills up the catchcan/breather with a off color liquid guessing its a combination of condensation/oil mist from the valvecover. 5 psi shouldnt need to much to prevent crankcase pressure from building up, but it just doesnt seem like the rings are sealing well or something. Actually pulled the oil level down after a few pulls on the dyno (only made 3 or 4 MAX) but doesnt seem to consume much driving around, although it smokes. He said it seem like it always drops till it hits a certain point or something, could the oil drainback be not working properly and its building up in the turbo, leaking thru turbo until the level is low enough that it drains back properly?

Thinking valve seals, (some heads are known for this) rings, or PCV just not cutting it. Anyway to test these things? Gonna do a quick compression test on a few cylinders, and then leak down on them I guess should be the next step. is there a "blowby gauge" Maybe pull intake off to look at leakage past valve seals? I hope its not a single cylinder problem, plug access is horrible on these things.

 

oil like that, sounds like a ring or a piston to me. best case the turbo needs a rebuild. jmo.
power can fool you, my buddy made 550 with a half melted piston!!
plugs covered in oil, sounds like rings. do a leakdown on it, that will rule out the turbo

 

If its a TTI street kit check to see if the drain fitting in the pan is lower than the turbo, then you can try to shorten up the drain hose to take the "U" shape out of it (the slack) that might work it did on mine BUT if the oil has been backing up in the turbo for awhile it might have ruined the seals which isnt too expensive to replace. 4 psi doesnt sound like enough to smoke the rings but who knows what the car has been through. As far as PCV goes using vaccum from the inlet hat works good but only if its hooked to the LS6 stlye valley cover not the valve cover, LS6 valley cover with VC breathers works great, I modeled mine after Mighty Mouses set up. Also if you were pulling oil into the inlet then you might have residual oil in the intercooler which might take a little while to work its way out. This is just my opinion based on problems Ive had in the past, i am not an expert.

 

Sounds like oil from the turbo.Take the inlet tube off before the throttle body and see if the oil is in there.

 

Everything you guys have said, is what I was thinking.. but not the nicest answers. If there was damage it was already done. Oil is not your friend in the cylinder.

Sound like good plan of action?: do leakdown, pull inlet hat off, pull intake, if at that point PCV seems to be an issue like breathers arent doing enough, then do LS6 valley cover and let the turbo pull on crankcase with an air/oil separator inline to pull out any remaining oil vapor? The guy already spents lots of dollars, and its been months so far without the car, but now that my hands are in it, I want to ensure as little problems remain as possible. I put a pretty conservative tune in it on the dyno, torque curve was pretty smooth, as it should be for 19 deg timing, 11.5:1 air/fuel at only 5 psi - trying to avoid a problem if it is ingesting oil like I think it is

The turbo was just rebuilt when another shop put it together, due to the oil backing up into it. Exactly what Im saying. 5 psi not much, but on stock injectors, no tune with about 28 degrees timing up till @4500 rpm, with oil in the charge it saw wot boost so who knows? Oh yeah, the wiring harness is beat up a little, when I first saw boost the day I was tuning it, the MAF reading was tripping out loosing connection. Not good Slowly working out all the bugs though