Hey Guys,

I hear this odd noise while I am accelerating. It is not coming from the engine, it is coming from the bottom of the car. (as far as I can tell)
I do not hear this when the car is in park and I step on the gas.

This noise appears to be present when my car was parked outside in the sun and not so much when I had my car in the garage. (this may have nothing to do with it)

This noise can be described as a rustling or buzzing sound, I wish I could record it.

I am thinking it may be some kind of insulation around the exhaust pipe or the catalytic converter that has been rusted or "burned" up.

I know this is not much information but any help is greatly appreciated.
Thanks, F1.

 

A common source for a rattle is where the heat shield bolts to the catalytic converter. The heat shield will rust or crack and can cause a vibration.

 

Thanks for the quick response, this was my gut feeling too.
So should I just take the heat shield off and forget about it? Or would you recommend replacing it? Thanks.

 

Sometimes the shield rusts around the bolts; if so you can simply use larger fender-washers & put it back on. Or hold it with hose clamps.

There's several heat shields. If the rattling one is between the exhaust & the floorpan, I'd figure out some way to hold it in place (or replace it). (You don't want to set the soundproofing tar on fire while you're driving.)