Widowmaker[X]

06 GT, Axle-backs. When I start up my stang I occasionally get a rattle which I believe is coming from the exhaust itself. I would describe it as more of a "buzz" that only occurs at a certain RPM. It happens for a brief second as the car climbs through the RPM's and then again after a few seconds as they fall to idle. It sounds metallic.

It is not my hangers touching the frame or loose bolts or clamps because Ive been through all those problems before.

I got down under the rear and tapped on the pipes and seemed to pinpoint something rattling inside the right side exhaust pipe, somewhere near the tip. Is there anything inside that could possibly come loose and be trapped in there?

Thanks...

mapitts

You did not say if they are OEM mufflers or not. I think that OEM mufflers are baffled. How about taking that muffler off and giving it a shake. I have a friend who has a bulldozer that had a terrible knocking sound in. We looked all over the place for it. Turned out it was a broken baffle in the exhaust.

onederful100

agree.
could be a loose baffle. flowmasters are notorious for this.

Nuke

Torque the axleback clamps another 1/2 turn. Some of the axlebacks are notorious for a metallic scrapping sort of sound or buzz around 1800-2200 RPM, usually when the pipes are cool on initial startup. If it's not that and you've already confirmed it's not the hanger-to-frame contact, then I concur with bad baffles.

Widowmaker[X]

So, heres a video I shot this morning where you can hear what I'm talking about...

http://www.youtube.com/watch?v=-ixdsZikGtE

You can hear it once at the 12-13 second mark and again around 17-18 seconds.

Widowmaker[X]

After hearing it a few more times I'm not so sure that it is coming from the rear as I suspected... Sounds more like from under the middle of the car somewhere... I'm thinking it may be the heatshield now...

2cokeman

Still no mention of what exhaust it is?

RoushGT

I had my passenger side catalytic converter come apart. The pieces would drop down and lay in the bottom of the pipes and rattle.

FordService

Hi Widowmaker[X],

If you are unable to determine the cause of your rattle, then I suggest having your Mustang diagnosed at your local dealer. They are in the best position to determine the why it is rattling and recommend solutions. You can locate the closest one here. Please let me know if I can be of any additional help!

~Natasha

808muscle

I had a rattle in my exhaust once. Turned out the exhaust guy, when he had cut my pipes he let a piece of metal fall down the pipe. It would just rattle around in there. If your pipes have not been cut I would guess a broken baffle or after market cat failure.