YO i got a 00 s4 sometimes i hear this loud and real fast ticking sound? i was told thay might be the injectors it cant be the lifters i know what thay sound like but the ticking comes on and go's of somtimes its LOUD AND FAST like i said not steady all the time also i changed my oil and started it up and there was a loud grinding whisle sound not sure?..i think maybe no oil in turbo? it can from passinger side