I have just repaired my daughters 1.9 TDI 2006 with smokey exhaust, it's previous owner had changed the turbo, boost pipe and a long list of items. I noticed the oil level going up on the dip stick, I got the level spot on and monitored it, it rose again. I changed the oil and filter, and the tandem fuel/vacuum pump which was leaking fuel into the head via the camshaft. Oil pressure 1 bar, fuel 150 bar pressure. It may be worth checking the oil level, as this caught out the VW garage and Audi tuneing company who had cost the previous owner a lot of money. Hope this helps, just encase the turbo repair wasn't the cause of the smoke.