Just discovered this within the past few days in my 2006 MMH. When I'm at idle, there's a rattle coming from the engine bay, and it sounds like it's coming from near the accessory belt. I can reach the accessory belt tensioner and tighten up those bolts if it's loose, but it changing the belt doesn't look easy. How easy is it, and am I looking the the right place for the fix? Anyone else with experience with this?

 

Lots of things in that area can cause a rattle but if it seems to be coming from the tensioner, more than likely the bearings in it are bad and the tensioner will need to be replaced.

 

That's what I suspected. $50 part at the store, plus another $12 for a new belt, but looks like a bear to reinstall the belt.