Just today I noticed a funny tapping noise in the engine in my '02 E320 4matic.
I think it just started today. I accidentally stepped on the accelerator while parked and revved up to almost 6000 rpm for a second or two. half hour later I noticed a tapping noise in the motor. It doesn't happen all the time. It stops and starts on its own.
What could it be?
I'm hoping it's not a valve. (probably is)