i have it too.. ~8,000 miles on my '03 evo, and decelerating from 3500-4000 rpms i get a rattling (like little marbles rattling around somewhere). also, i noticed at a stand still, if i rev my engine in neutral with cluth pedal out, it sounds little more vibrating than if i rev my engine with the cluth pedal in (meaning, with the clutch pedal in, the revving sounds much more cleaner).. is this normal or is this related to clutch/throw-out-bearing/transmission problem?

thanks..

 

I just started getting this with 13,600 miles on my Evo. One day it wasnt there then all of a sudden I get a sound like a loose bolt rattleing in a hole when decelerating in 3rd or 4th above 3k. It seems very tied to the vibration caused by the exhaust but I have spent days tightening everything in the car and I cant get the sound to go away. I have put a microphone on the tranny and the engine and its not coming from either of those places. The sound appears to come from the front left portion of the car (Drivers side front). Bugs the crap out of me but I dont get any drivability issues and the car runs smooth.