Rattle in muffler at 2500 RPM's

[Red Line]

I have a Nissan 2002 Xterra SE supercharged model. I've had to have the muffler replaced four times since I've purchased this vehicle. I am currently setting up another appointment to replace the muffler a fifth time. The dealership is at a loss at what it can be. Each time the problem happens I get a vibration rattle within the muffler at 2500 RPM's in all gears. The dealership states its the baffles within the muffler but does not know what is causing the problem.
I believe the factory supplied muffler cannot handle the high RPM's that I sometimes push the vehicle to perform.
In each case, the symptoms have been identical where the rattle happens at the 2500 RPM mark. Each time the muffler was replace the rattle stopped but then returns.
What can this be?

[Pbum5]

I had a similar problem with my 2000. It was a Heat shield on the exhaust.. I had them cut them off and the problem was gone.. a Simple Fix..

[Red Line]

Thanks for you response Pbum5. I hope its that simple.
Curious though that after muffler was changed each time, the rattle stopped but return between 3K to 5K miles. Plus it only happened after the muffler heated up.

[Pbum5]

Originally Posted by Red Line

Thanks for you response Pbum5. I hope its that simple.
Curious though that after muffler was changed each time, the rattle stopped but return between 3K to 5K miles. Plus it only happened after the muffler heated up.

Yeah, I don’t know about that.. My guess is when it heats up it expands and that’s what makes it rattle. I had the problem with one shield..Then had it cut off.. Then about 6 months later the problem came back. It was another heat shield and I had that cut off to and It hasn’t come back since.. the dealer charged my $40.00 buck each time.. I don’t know if that is what is wrong with yours, but it might be worth checking out..

[ChrisOB]

I have a 2001 that makes a tin-like rattle at certain RPM's. I suspected one the the many heat shields on the underside.
Which ones caused you the problem? Where should I start?

[OffroadX]

Could be any of them, get under there and see what's loose...