I am looking to test drive and buy a 2012 Black Edition Audi A5 Auto 3.0 S-Tronic. The car has done 166k on the clock which I know is high mileage but has full-service history with services every 18k at Audi dealer garage. I have been told that I should ask Audi about the chain but they say its not a serviceable part. Then others say that it should be changed with such high miles. I don't know who to believe or what the costs of a change would be. Any help appreciated or things to ask/look out for appreciated.

As long as it doesn't rattle on startup you should be OK. If/when you go to view it, make sure that the engine is stone cold. Open the bonnet, and stick your head under it towards the back of the engine. Get someone to start it and listen for cam chain rattle. If there's even the slightest suggestion, walk away. That said, it was only really the early 3.0TDIs that suffered in this respect, so with a 2012 motor you should be OK.

24 minutes ago, Rudis_Dad said:

That said, it was only really the early 3.0TDIs that suffered in this respect, so with a 2012 motor you should be OK.

Mine is a 3.0 TDI lol