rattle sound when idling

[BuickMan]

something is rattling under the hood on the passenger side when I'm idling. I can't tell if it's the engine or something else. There doesn't seem to be any change in engine performance. car still starts OK. Anybody know what it might be?

[AL]

possibly an exhaust heatshield... Pop the hood while its idling and listen for it

[xtremerevolution]

possibly an exhaust heatshield... Pop the hood while its idling and listen for it

 

x2. Been there, done that.

[mediabandit]

Also check your A/C the clutch goes bad in them and it sounds like a marble in a tin can when it sits idling.

[jtwmechanic]

pull the belt and start the engine for a second if you don't hear the rattle then that will eliminate the engine or harmonic balancer. if you still hear it then check the balancer, they have been known to come apart. after that definately probally the exaust or something?

[RobertISaar]

i have roughly half of the exhaust heatshielding pulled off of the MC(all of the underside pieces, oddly enough), but i never heard them making noise even when they were just barely holding on...

 

other vehicles however, you could see the damn thing tapping whatever it could touch, especially during a gear change or reverse/drive transition.