My 99 Trans Am sounds like it has pebbles in the motor when it gets up in the rpm's. Sounds like it is coming from the top area of the motor, possibily somewhere in the valvetrain. Only does this at high rpm's when the car is in being driven. Sitting with the car in park and revving does not produce the sound. So it seems to only occur when the car is under load. Usually occurs when the car gets close to 5-6000rpm. BTW, this is an automatic car. Any ideas? Thanks in advance to all those who respond!

 

all automatics i've been around do that.

 

Anyone else?

 

Car could be pinging/detonating. Have someone check your a/f ratio under the same conditions that it happens.

Detonation can potentially kill the engine. It's NOT good!!

 

Mine does that too, and it does sound like top end parts. The car doesn't consume ANY oil at all, and the oil is pretty clean. I wonder what it is as well??

And mine is a 99 A4 as well.