put 3k miles on the S3 this summer no problem. Its in my garage for the winter and i started it up tonight and it sounds like it knocks? Didnt do it when it first started but when it got up to temp it does. I know their a noisy engine but i dont remember it being that loud. Any ideas? Good clean oil, didnt do anything wrong just started it, let it get to temp and did a few 4k revs. Any ideas?