About 6 months ago I had a problem where my car would put out a cloud of light grey/blue smoke every time I pulled away from idling. At the time I cleaned the egr, all the intercooler pipes, checked the turbo and took out some oil as Audi had filled it to just over the max mark. About a week after doing all this it just stopped by itself and has been fine since then. Then, about a month ago I was getting a cloud of grey diesel smoke on cold start up and it was a little lumpy for about 2 seconds, but I put this down to the very cold weather. Just to be sure, I put a double dose of Millers Diesel treatment in with a full tank of Shell V-power. Shortly after this the weather changed and my start-up smoke totally vanished, only to be replaced with my old problem of smoking when I pull away. I'm lost now. It can't be anything like turbo, valve stem seals or tandem pump otherwise it wouldn't have sorted itself out last time and been perfect for 6 months. I've ran a VCDS scan and found no faults. I then checked the injector readings with VCDS and got the results below, which I believe are acceptable: Inj 1 - 0.00 Inj 2 - 0.35 Inj 3 - 0.30 Inj 4 - 0.00 Has anyone got any ideas why the smoking has returned? At the service when they overfilled the oil I'd also had a new sump fitted, so I'm wondering if something is wrong and the dipstick might be reading wrong. I'd just topped up the oil before the smoke started again, but only 2/3 of the way between min and max because I'm nervous of overfilling it. It doesn't seem to be using oil any more than normal and the coolant level never moves. Help me please! I want to sell the car and get an A3 black edition, but nobody will buy it with it smoking like this.