I have a 00 xj limited 4x4 that rattles under light to moderate load around 1800-2200 RPMs. the rattle is able to be reproduced when jeep is on jack stands. I have replaced the cat and muffler, checked all the drive shaft components, and the exhaust manifold. When the jeep is jacked up I can trace the rattle, that sounds like a piece of loose metal "pinging" sound, to around the starter/bellhousing area. This noise is driving me CRAZY! I have taken it to multiple shops and no one has put in the time to give a me a positive answer to what it is. I might try to remove the starter and see if I can see anything wrong with that. Any advice would be greatly appreciated.

 

Loose Heat Shield?

 

torque converter?