I have this sound problem..

[00FlowCamaro]

So I have this noise that likes make itself known:

1) When the cars shifts itself up (I have an A4)
2) Sometimes when I'm just going along the road
3) Does not make this noise idling (Neutral or Park)
4) Can't be made by powerbraking
5) Does it a lot when under torque or power

People at CamaroV6 gave me suggestions of exhaust leak...couldn't find one or backpressure, and im pretty sure that isnt the problem either. I have a Cat-Back Flowmaster American Thunder exhaust. Please help.

[97rs4life]

from that post nobody can diagnose it as you didn't tell us what it sounds like or include a sound clip.

[00FlowCamaro]

It's really hard to get that sound clip with having to get it at the right time and then driving with holding something where you are actually able to hear it, I'll try and get something, but the quality will be shiat!

[SlipStreamZ28]

well then try to describe the noise, is it a whine,rattle,grind or what?

[meissen]

Have you notice any performance decreases from this noise?

[JoeliusZ28]

sounds to me like a worn mount thats allowing an exhaust component to touch something else under torque.

[00FlowCamaro]

From what I've heard it can very. When the noise is at its very least it will make some kind of air noise, like a leak or crack. When it is at its worst it definetly sounds like a rattle. The exhaust is sound tight, checked every clamp. I've tried going over and under checking out the headers, but can never really get a good view of things. Someone may have hinted at a crack somewhere in my header, maybe.

And there are no performance decreases that I am aware of. The car doesnt overheat, battery is charging fine and the oil level is superb.

There was for awhile in the cold weather where i could see steam coming from under the hood. It looked like it was coming from the back of the engine. Not sure what fluid, my dad said radiator fluid...but the hell would it leak back there.?

[SlipStreamZ28]

Well If I remember right the LT1's have a coolant line that runs back there to do something for the intake, maybe the LS1's are the same?

[00FlowCamaro]

Mine is a V6, not to sure if that is the same on every engine.

[97rs4life]

Well If I remember right the LT1's have a coolant line that runs back there to do something for the intake, maybe the LS1's are the same?

yea his is a v6.

[thursday12889]

If it was coolant you would know because of the smell, any fluid you should know from the smell. If it didn't have a smell maybe it was just water because the seal in the back of the hood is bad and water is leaking down onto a hot part of the engine causing it to steam. I don't know though sounds like a good guess to me as far as the steaming/smoking part.

[00FlowCamaro]

The sound also seems like it could be coming from underneath, say the Cat. My cat is still from the factory, and was wondering if somehow this could be it? The cat isnt hitting a friggin thing, but maybe sometihng inside might be loose to cause the problem?

[JoeliusZ28]

The sound also seems like it could be coming from underneath, say the Cat. My cat is still from the factory, and was wondering if somehow this could be it? The cat isnt hitting a friggin thing, but maybe sometihng inside might be loose to cause the problem?

I was just going to suggest the cat. When one of my cats went bad the thing made such an annoying rattle I wanted to crawl under the car with a hacksaw. so thats what i did lol.

Crawl under the car and punch the cat with your fist (wear a glove ovbviously). if it rattles your cat id toast.

[00FlowCamaro]

Yeah, mine has this little *ting* noise when i hit it. Would that be worse when im driving you think, when the sound occurs?

[JoeliusZ28]

Yeah, mine has this little *ting* noise when i hit it. Would that be worse when im driving you think, when the sound occurs?

no. mine was most annoying at idle. it wasnt loud, just a constant audible rattle. i would hear the noise reflecting off other cars in traffic and it sounded like a POS. Im sure mine made the noise under throttle, however the exhaust was making so much noise at that point i probably couldnt hear it.