Sounds like a heat shield rattle....

[Stl_Denali]

I’ve been experiencing a noise which sounds like a loose heat shield rattle coming from I believe the front driver side – I can almost feel the rattle on the floorboard. Its not a loose shield as I’ve clamped them all with belt clamps.

 

The rattle happens intermittingly, both while driving or just sitting idle. If its rattling and I rev it up a bit the rattle will speed up then go quite. I cannot get it to rattle with the engine off by rocking the truck.

 

I’m thinking its something to do with the exhaust, maybe the flange where it connects to the engine but its hard to check. I can’t find anything loose and when I attempt to pinpoint the rattle its stays quite... lol.

 

Just wanted to see if anyone had a similar experience or has any suggestions. Thanks!

 

 

I had my tranny rebuilt last August, but I honestly cant remember if the rattle was there before or not.

 

It is a true rattle, tinny sounding… doesn’t sound like a leak in the manifold nor a wheel barring.

[govener71]

I had a squeek that ended up being the flange at the end of the y pipe. Just a loose bolt that needed to be tightend. Just bang around on the exhaust with you hand and listen close.

[Gone Again]

Take a rubber hammer and rap along your exhaust system starting at each exhaust manifold. Pay particular attention to area around the catalytic converters. The insides of the converters may be broken/loose and vibrating.