my 535i valves seem real noisy.iv heard people say they were alway noisy even from new ,but sound a bit far fetched to me, i have adjusted the gap a few times to the required size but still chatter away. now im thinking it could be worn valve eccentrics, iv been quoted $17 each for them and need 12!, adds up real fast for somthing in not sure will solve the problem.has anybody encounterd this?. can anybody help