al99m

2004 rx8 automatic 95000 miles. i am curious as to what happens in the engine control system at 4500 rpm (opens another intake tract ?, opens another exhaust port ?)
my problem among others is that at exactly 4500 rpm and above i get a raspy rattling noise. in gears 1 and 2 it is a raspy noise like maybe a small exhaust leak. but in gears 3 and 4 it it a very loud rattling noise along with the raspy noise. since it happens at exactly the same rpm all the time i am guessing that something is going on in the engine control system that is supposed to start at 4500 rpm. does anyone have any ideas on this ?

VashGS

Hum you get any codes? When last time you replaced coils, wires & plugz?

al99m

mil light is on due to gas cap not tightened but no codes are listed. coils, wires and plugs are on the list of things to do but i dont see how this could make the noise. i dont get any miss that i can feel

VOODOO8

One suggestion: do a search for "marbles in a can" and find a thread with an audio track. Can also search other places like You Tube. See if your rattle sounds similiar.