I own a 1995 Ford Mustang GT, 5.0, 5 speed, and I've realized I'm having an issue that's annoying and embarassing. When I turn the wheel to the right, /sometimes/ I can hear what sounds like my tire rubbing against the fender well. When this first started happening, I chopped it up to the fact that the rear tires were massively oversized. (18 inch 265 something big foot tires. ) So I had those replaced with a lower profile 18 inch tire. (245ish.) All around. This seemed to lessen the degree of the rattle-y grindy sound, but did not kill it off. I then started to realize that I heard this sound under high acceleration. (4000+ RPMs.) My assumption next was that the shocks were probably stock, and the rear end was squatting onto the tire. Had the shocks replaced, and to no aveil, as the noise was still present. My girlfriend then suggested that it might be something as small as a marble rattling around in the trunk; took EVERYTHING out of the trunk, rattle was still there. Thought it could have been the license plate frame that was loose; took it off, still rattled. Got annoyed with the ricer wing that was on the back; took it off, still rattled. I'm wracking my brain trying to figure out what could be causing this. Can anyone point me in the right direction? I'm new here, so be easy on me. =)

Known Aftermarket Parts:
- CAI
- Exhaust (I don't know what brand as I haven't felt like looking.)
- 18 inch rims and tires.
- Wing (Removed.)

P.S. Could it be the insulation in the trunk? I forgot to mention in my post that one side of the insulation is loose, but I figured it wouldn't make that much noise, and ironically, at that RPM level.

 

Well we kinda need mor einfo. Like where are you hearing the rattle? with the car in neutral and parking brake on does it still do it? I have heard exhaust do this at times when there is a crack or broken piece around it. It could also be a heat shield around the exhaust. Please provide a little bit more info.

 

At a low RPM idle, (800 or so,) no, the noise is not there. I haven't tried revving it to 4000 in neutral, though. It's a little late, or I'd give it a shot; I'll do it first thing in the morning and let you know. Other than that, it seems most prevalent when I'm on the highway accelerating, (merging onto the interstate for example.) As soon as I hit the 4000 RPM mark, it sounds like the entire back end of the car is rattling or shaking. I, as well, thought it might be the exhaust, but the other problem is that sometimes when taking a right or left hand turn, I can hear the same rattle, which makes no sense to me. If you can give me more examples of situations where I might hear it, I'll tell you what happens. It's just that it's 2:30 in them morning, and I'm a bit brain-dead myself. :-P

P.S. Thanks for the quick reply!

 

UPDATE: I tried revving up to around 4k RPMs at idle, and it doesn't make the noise. I've also realized that it happens when I'm accelerating away from a dead stop, and when the back end squats down under high RPM acceleration. Could it be the tire rubbing the fender well?

 

UPDATE: I've also noticed that this sound occurs when I take off from a dead stop, too, when the weight of the car is transfered to the back. Does anyone have any advice what so ever?

 

I would double check clearance on the tires. Check if one has markings on it like it's been rubbed. Next I would put jacks under the rear axle and put it in drive and listen

 

Go check the exhaust. There may be a part touching the underside. Heck, mine was rattling at it turned out that my exhaust was touching the upper control arms, the frame and the gas tank! It only rattled under acceleration because more exhaust gasses were passing through it causing it to move. I'm almost positive its this.

 

My buddy and I were talking about it today, and I took him on the highway for a pull to listen; he thinks it's the exhaust, too. We're going to jack it up tomorrow and check for clearance just to make sure. But yeah, that makes the most sense, honestly. I checked the tires for wear, as the guy above you said just to make sure, and the profile we're using now seems to be just perfect. Thanks for the replies; I'll keep you guys updated and let you know, but I'm starting to think it's the exhaust, too.

 

UPDATE: So, it turns out it was the tail pipes. They were either mounted too close to the gas tank and rattle against the heat shield on it, or a loose hanger. Either way, we've got the exhaust dumped now, and it sounds a million times better. Thanks for the help everyone!

 

You're welcome!