C5 01 4.2 engine knock at idle
 

Just noticed the engine knock only at idle when the engine is fully warmed up, and in gear sitting at a stop light. Noticed no loss in power, still runs like a beast! But knock is worrying me. Goes away the second I accelerate. Any ideas?


[/LIST]2001 Audi A6 4.2l V8-83k miles- h & r adjustable coil overs, k & n cold air, supersprint cat-back exhaust, bbs gunmetal 255 all the way around on toyo's