I recently purchased a 02 2500 hd with the 6.0. Love the truck, but have a few noises I can't figure out. First; there is an exhaust leak somewhere between the exhaust manifold and the cat. I have replaced the flange gasket between the actual exhaust pipe and the drop down from the manifold...still leaking. It only does it for the first 10 miles or so after start up and then quits. Second; while backing up slowly there is a low pitch intermitent squeak coming from around the rear axle or drive shaft. Not going foward, but only in reverse. It looks like it has a new u-joint on the rear drive shaft, but not sure. One more; there is a light rattle under the drivers side dash, I'm sure it's nothing mechanical but just extremely annoying. Any help advice on any of these would be much appriciated. THANKS!!!

 

not sure on the problem with the exhaust? but our 2002 2500 silverado had a light raddle, it sounded like it was coming from under the dash but it was really the plastic cowling at the rear of the hood we used some clear silicone and it seemed to do the trick. we have a bug deflector on the truck that also make the side mirrors vibrate so bad you cant see whats comin up behind you. thrun out the truck isn't too areo friendly

 

thanks for the input twizzle12. It sounds like the rattle is coming from directly under my dash though. I can push up on everything under there while I'm driving and it will stop, but it's kind of hard to climb under there going down the road, but I'll definitely check out that cowling.