[oo7]

rattle from underneath seems to happen after deceleration

I've got an 07 4wd Trailblazer wit about 107k on it, and I just stated noticing a rattle that I hear more when I'm driving past something big. I thought from what I read it could be the heat shields and stopped worrying, but then I realized I never hear it when I'm stopped even if I rev it. Then I read somewhere it could be the rear transfer, but it sounded like they updated that problem before 07. I read somewhere else to get the fluid changed in the transfer case, and that might be it, I never got that done. JiffyLube didn't have the fluid the last few times I asked.

Something I've noticed is that it sounds about the same in the parking deck as it does on the highway which is why the heat shield theory sounded better than something in the drive train. But when I rev it at the red lights, I can't get it to happen.

Any ideas?

:coffee

 

[oo7]

still rattling, could it be the resonator?

I got the fluid changed in the transfer case, and I got the rear brakes and rotors replaced, but the noise is still there. I can't get it to happen when I'm in park, but it happens in the parking deck and out on the highway and the sound isn't any different.

Seems to be from the rear but I could be wrong. I parked it with the rear tires on the sidewalk and slid under it and checked the heat shields and exhaust. It all seemed ok to me. I found where the shield on the gas tank was missing a post that a clip goes on and another clip was loose, but I tucked a plastic bottle cap between the shield and the tank, gave it a drive, heard the noise, then parked it and looked up under there quick and the cap was still there.

I saw some posts about the inside of the can in the back of the exhaust rotting and breaking loose and rattling. If its that, I'd be tempted to just live with it.

I'm hoping its not something broken off in the pumpkin ball rattling, but it seems to be functioning fine.

The other thing I've read about is that it could be a bushing on a sway bar or another suspension component. The suspension has always been overly bouncy, but I don't notice the rattling more when I go over speed bumps or rough pavement either.

I just don't want to be left stranded when what ever it is goes completely bad.

:coffee