VW is going to buy back my and I'm looking at a with the 3.0 V6 diesel and low mileage. I've done a search for problems with reliability with this engine. I'm concerned about the timing chains being located on the rear of the engine, and having to have the engine removed to replace them. I'm a retired airline mechanic and have always done all my own auto maint. except for wheel alignments but don't intend to do any engine removals on this Audi. If anyone here has a Q5 diesel with some miles on it, I'd be grateful to hear of any problems with these . I know they have to have a longer service life than timing belts, but I'd like input from anyone who has had these chains replaced. Cost, downtime, etc. Thanks for any time and help.