[CycloneGTO]

This is a strange one. I occasionally hear a noise coming from somewhere in the back of the car. It sounds like something metal bending back and forth. In fact, it sounds exactly like if you took an old school car antenna, bent it a little bit, and then let go. It's pretty rare when I hear it, and it seems to do it the most shortly after I start the car. I can usually reproduce it by going over a bump one wheel at a time (i.e., at an angle to induce a sideways rocking motion) going at least a few miles an hour.

I've looked under the car, and I don't see anything that could do it. I've also looked in the trunk (but not under the liner). The only thing I can think of is that it's either 1) gas sloshing around in the trunk, although I can't imagine how that would sound like a metal antenna shaking back and forth or 2) something else in the vicinity of the gas tank.

Also of note, I installed headers and exhaust recently. Before that, it used to sound quieter and more like a quick knocking sound. It literally sounded like there was a woodpecker in the trunk or something.

Any ideas?

 

[westell]

Much of the cat back exhaust is hung on rubber. Try moving exhaust back and forth at rear of car to duplicate. I had a similar noise, clunk,clunk on cold start and that's what it ended up being.

I also had a loud whine coming from passenger seat area on wide open throttle, so now I leave wife at home:turbonaug

Sorry - couldn't resist:drink:

 

[CycloneGTO]

I'll give it a shot. Did you get the noise to go away, or do you just ignore it? Mine doesn't bother me since it rarely happens, I just want to make sure nothing is wrong.

 

[westell]

When i replaced the SLP LM1 mufflers (way too loud w/ L/T's) with the Magnaflows we were able to get rid of it.

I have the SLP LM1 exhaust pipes still.

Of course, I have one of those slow 04's with dual on driver's side:gears:

 

[CycloneGTO]

That was it. The rubber pieces connecting the hangers on the passenger side are very tight and stretch outward from each hanger up to the car. As a result, the pipe doesn't hardly move.

On the driver's side, the way the hanger bars are designed on the Magnaflow, the rubber connectors aren't as tight, and they extend inward instead of outward as the reach up to the car. As a result, they don't do a very good job of limiting lateral movement. As a result, the muffler would occasionally hit the heat shield. I played around with it and got it a little tighter. Problem solved.

 

[westell]

cool ***elsatriot: