Loose Rattle Mainly at start up...08 Endy SE
 

Hi, we have a beautiful 08 SE with only 46K on it, for the last 2 months it
has been making a noise like a heat shield is loose sounds like somewhere in the alternator area at start up. Lasts about 2-3 seconds then goes away, but will reappear to a lesser degree when accelerating/driving. Also makes noise when engaging R and backing out of garage in reverse when basically cold

The only thing I can find is when I hit the cat under the truck with my fist I hear something rattle inside there. Do we need a new cat? No check engine lights on, I think Mit will replace under warranty as we have 5/50 until mid November (service date (8/29/08) Is this right?

Could it be something else as well? Thanks for your help!

same here
 

I have the same problem. ever figure out what it is?