As an Audi 2,0 TDI driver I have the following question on the new TDIs (also some Volkswagens). I've picked up that the exhaust tailpipe colour on some are almost white – the same as in the older days with leaded fuel after a long journey. What is the reason for this? Is it only applicable to a certain brand of diesel? No dealer seems to be able to explain it.
S van SCHALKWYK – By e-mail
A white deposit, or even white smoke, on a diesel engine normally indicates water droplets mixed with unburned fuel. This occurs quite normally after a cold start, but goes away as the engine heats up.