FIXED? Help diagnose my smoking issue... FIXED?
OK here's the deal.
When the turbo was being rebuilt, the builder called and said the oil inlet fitting on the turbo was plugged with debris and that contributed to the bearing failure.
When I got the turbo back and installed, it started smoking out the exhaust after driving for a while. I called the builder, talked to a couple of guys on here, and was told to put a nitrous jet in-line to restrict the oil flow to the turbo. Did that, still smoked. Went with a smaller jet, still smoked. Put an in-line filter in, still smoked.
This past weekend I replaced the drivers side head. Reason being is there was oil on my front plug. A couple of weeks ago, we found a bad valve seal and replaced that hoping it was the problem. Still smoked.
Typically, the best I can tell, it would only smoke at idle. Today on the way home traffic was at a crawl on the freeway and even driving at slow speeds (10-15?) it was smoking bad. We're talking plumes of blue smoke rolling out from under the truck.
So I get home, and am racking my brain trying to figure out what it could be. I thought maybe the oil drain was plugged. Take it off the turbo side, blow through it, hit resistance, then it clears all the sudden. I think to myself that may have solved my problem. Call the builder, he says it might be. Drive it around, smokes a little, stops but the starts later on just as bad as usual.
Possible causes:
1.) My drain comes off the front of the oil pan off a straight nipple. It then dips about 3" or 4" to go under the crank pulley, and then goes back up and to the turbo. The builder today said that dip may be trapping air, forcing the oil back into the turbo and making it blow by somehow and into the exhaust. So at some point, I'm going to put a 90 degree elbow off the oil pan so the hose runs continuously "uphill" with no dips.
2.) A bad valve stem seal on the passengers side?
3.) According to the builder, there is a piston and ring (similar to the piston and ring in an engine) in the turbo and is the only likely place for the oil to blow-by. He said the chances of the ring being bad is extremely slim. But I guess it's an option.
4.) I'm going to pull the downpipe at some point to see if the oil is truly coming out of the turbo. Or I may pull the crosspipe to see if it's coming out either the exhaust or turbo manifold.
Any other ideas?
