16vsilverstreak

The A4 in question is still covered under the Audi extended warranty. Would a failed cam, follower cause a crack/hole in the back of the cam cover? The crack/ hole is bottom of picture above electrical line.

The answer is yes. The failed cam follower grenaded, the oil pump spread shrapnel all through the engine, scoring bearings in the bottom end said Audi. After first inspection they said new HPFP, follower, intake cam, cam chain, and cam cover. I asked about bearings in the bottom end. Service said they would pull the pan and inspect. When they discovered the bearing scoring in the bottom Audi instructed my Audi dealer to replace the entire engine. This was covered under the 10 year from date of delivery or 120,000 mile extended warranty .
If your car is over 120k replace your follower as part of regular maintenance, if you are under 120k you could roll the dice and maybe get a new engine from Audi.