I have a 2011 A3 2.0 ltr tdi. The dealer says change oil at 5k for the first oil change then at 10k there after. The oil seems to get black very soon after the oil change. Is it ok to use a diesel engine flush additive at a quick lube shop to remove sludge and deposits in the engine? The quick lube shop says it ok to use and will not void warranty. Tim
And to add to what Mr. Bang said -- don't ever take your TDI (or any other car in my opinion, but especially a TDI) to a quick lube shop. Ever. They have ruined more motors than probably any other source.
Your TDI has very specific specs for fluids and lubricants, serious damage may result from ignoring them. Wrong oil can lead to expensive emissions system failures. Your Quicky Lube won't use the right oil. They often strip drain plugs, over and under fill your crankcase. They try to sell you services you don't need, and then screw it up to boot.
Change oil at 10,000 mile intervals. More often offers no advantages, and too frequent a renewal of detergents may lead to excess wear.
Diesel oil always turns very dark, almost immediately. It is formulated to keep soot in suspension, and Diesels make soot. Get used to it.
P.