I have noticed a distinct rattling sound coming from my tail pipe when I am parked and idling. After some experimenting I realized it only happens when the AC is on. If I turn the AC off it immediately stops. It will also stop if I apply a little gas so the engine is no longer idling.
This was all I could find from Googling:
you could have an exhaust shield that comes loose. The added load placed on the motor from the A/C system may be just enough to create such a rattle. There could be a loose pipe or hose that is made to rattle more with the added load of the A/C
Does that sound like the right explanation? Are there any other possible explanations? If so what are some solutions I could try to fix the problem? It isn't a serious issue, at least that I think, I might be wrong. But it can get annoying.
Thanks for your help.