Timing chains are supposed to be a 'lifetime' item, with no need to worry about the timing components during the life of your engine. Unfortunately that's not always the case. With no service interval to go by, the only thing to rely on is common symptoms for diagnosis. Symptoms can include chain slap, due to worn tensioners and guides causing a ?marbles in a can? sound, or the chains can jump or potentially snap from a failed guide. Since the 3.0TFSI is an interference motor, a snapped or jumped chain can cause valve contact with the piston head and cause catastrophic engine failure.