so finally rebuilt my engine, done around 500 miles since, mineral oil, many changes, blah blah blah, 8psi boost on a td04, fully forged engine and was coming home last night, hit boost a few times, started hearing loud tapping, pulled over popped the hood, revved it and heard a really loud knock, was 5 miles from home so i crawled it, knocking really loudly but sounds like its coming from the top end?! any suggestions?