hello everyone, i'm new to this site and the compact car scene, after building rear drive big block and small block cars for years, i have a 2000 cavalier z24 2.4 , car runs beautiful, but at high rpm around about 2800 to 3000 rpm the engine rattles, as soon as rpm goes down, the sound goes away, it idles nice and quiet and pushes out good, oh yeah and its a 5 speed, i really like this car and hope its not nothing major, because i do know these engines are hard to find , but as for anything like timing chains or head work, no problem, i just hope the engines not junk, the previous owner had the motor put in and said it had about 60,000 miles on it, i knew it had the rattle, it only needed a driver fender and door, and for 500 bucks i couldnt pass it up.

If the RPM gauge doesnt wig out at 2800-3000 (go up and down, stutter) then I dont think anything is wrong with the motor.

Maybe check your motor mounts.

i know its not engine mounts, everything is pretty tight, it idles nice and smooth, i drove it today and the rattle noise is more around 2300 rpm, right before you shift to bring the rpm down, if you shift early through every gear, you can get it not to make any noise, it only makes noise when its reved up, even if you rev it up in neutral, it kinda sounds like spark knock

I doubt its "spark knock"

Have a friend with you and ask them to rev it where its making noise and you look under the hood

Make sure nothing is shaking. Check and see if your exhaust is "firm" and not loose

yea, i knew it wasnt spark knock, it just sounds like it, everything is nice and tight, when its reved up nothing moves, it sounds like the noise is coming from the top , more towards the timing cover