I'm hearing a fast repetitive clicking sounds which appears to be coming from under the red valve cover at idle speeds. It is only noticable after the engine has warmed up. While reving the engine, it either goes away or is drowned out by the sound of the engine, but comes back again at idle.

Any ideas as to what it is? I dont think it can be normal.

2003 w/53K just got the car.

Thanks for any responces