I have a 2005 Rubicon and there is a rattle when riding in the mid range area. If you are just chugging along and barely applying any fuel there is a metal sounding rattle. Almost like a loose metal ring on a vibrating exhaust header kind of sound. I do not think that it's serious but would love if I could fix it. I'm sure my 85 250 Big Red had a similar sound.

Any thoughts???

Bruiser

 

My 05 Rubi is very solid and does not rattle. I would guess that you are right in that it is only a clamp or bracket that is not tight. I would try to run your hand over everything that you can reach and see if anything feels loose. If you can only hear a rattle and you can't feel any vibration when riding than it is more than likely something external. If you can feel the vibration than it could be an internal part of the engine and you should have it checked out. I really don't think that you have anything to worry about.

 

My 01 Rubi had the same rattling sound at idle, check the heat shield over the header pipe, I repositioned the clamps and added an extra one and it took care of my rattle.