My 03 max used to have an annoying rattling sound from under the hood. It only used to do it when the car was idling but that has stopped but when I rev of the car in neutral and the RPM's begin to come back down right around idle it rattles for a quick second and stops.

I have heard of rattling while driving or around higher RPM's but not around idle.

Does this happen to anyone or does anyone know what causes this??

 

possibly a rusted heat shield, but wait for the experts to chime in.

 

Unfortunately i had the same problem. In the end i found out it was the rear pre cat. The material was moving around inside of the case. The only way to fix it is to change the pre cats or put headers on. Once i got rid of the pre cats i got rid of the rattle. If you think this is your problem fix it sooner than later. The cat brakes down gets sucked back into the engine and causes oil burn. I know there are obx headers on ebay right now. Goodluck.

Here is a thread i wrote up
http://forums.maxima.org/5th-generat...questions.html

 

if it's not a heat shield or pre-cat, what else could it be? i have a similar rattle but when i rev it up the rattle sounds louder, then quiets down as the rpms drop. the sound comes and goes

 

My guesses are timing chains, main cats, something else in the motor? not sure tho