Strange New Noise
 

CheySha and I heard a strange new noise coming out from under my Vette tonight. Sounds like a vibration noise coming from the rear end area. We only hear it when its in gear. Goes away When put in park. I crawled under there to pin point were its coming from. Sounds like the front of the transmittion/torque shaft connection area. To me it sounded like the front trans housing area. Any ideas what the issue might be?
I have an automatic.

:squirrelrun:

Your general area might be kinda this general area description does not help alot. LOL.

Does it sound like metal on metal or just something loose sitting on the tranny bounceing round?

I would feel around to see if any of the harnesses have come off the cheesy little clips and is bouncing around. Also I can see the maybe the brake lines rattling might be the cause. Lastly gently put pressure on the exhaust tips when it makes the noise to see it maybe one of the hangers is squeeking.

Wellllll it sort of sounded like a tink clang rattle bang and it sounded like it was somewhere in the left of the middle right close to the back but towards the front.

Felt around the exhaust pipes for loose clamps & clips. Will check the brake lines and hangers tomorrow and let ya know.

To me it didn't sound like metal on metal but more like something metal rattling or and exhaust leak rattle.

EXACTLY where mine was.

:lolsmile: Your funny!!!:lolsmile:

Do you have NPP? I think they make a clang bang rattle tink noise instead of the tink clang rattle bang sound. If you have NPP the butterfly's could be rattling.

Sounds like a very good place to start. I can also picture one of the H pipe hangers with the spring ( I think your c6 uses the same) hangers rattling.

Have stock exhaust, and I saw those springs you were referring to but did not check them.

I am thinking exhaust somewhere, just barley touching something, you want at least 1/4 clearance from the exhaust. My header was hitting my subframe and was only noisy when in gear also, I found it by seeing rub mark on the header.

Sorry Wendy I was distracted by the WS game LOL... I don't know how to really describe it but maybe we can make an audio clip of it and post it along with a pic of the where it's coming from?

I figured as much! :lol:

We can do that tomorrow evening if I cant find the problem looking at the things mentioned!:yesnod: :cheers:

:squirrelrun:

I think it's more of a grinding noise... Like when a clutch gets too hot... That's almost what it sounds like to me...

Possible torque tube bearing going bad? Use a stethescope to listen along the driveline near the point where you kinda sorta hear the clang bang rattle tink grind.
Just make sure the Squirrell is up on a lift or jackstands(well supported) when you put it in gear and try to listen. You're nice and slim Wendy, but not slim enough to go hanging upside down under the Squirrell with a scope in your ear. :rofl:

:lolsmile: :lol: I loves me a good smart ass!! :rep:

a woman that will crawl under her vette and troubleshoot. the only thing hotter than that is if she was wearing a lacy g-string while holding a beer while doing it..

Try door # 3, tell us if the noise is there or not in neutral. (there is a difference) :D

A4 cars have different engine idle speeds depending on if "in gear", or "park/neutral". Based on your description, my inclination is that it's probably not something rotating, but is making noise by resonating at the lower idle RPM frequency which happens only when in gear.

You can test this easily, with the car on the ground, by placing the car in Drive, holding your foot on the brake, and giving it just a LITTLE throttle to bring the RPMs up off normal idle some (at/near/not over 1000 RPM). Does the noise remain or disappear? Or does it get worse?

And if you find there is a difference between park and neutral, it would quickly point to the tq converter, even though the resultant noise would likely be heard downstream.

:cheers:

No noise in park or neutral, All others yes.

"but is making noise by resonating at the lower idle RPM frequency which happens only when in gear." - YES

You can test this easily, with the car on the ground, by placing the car in Drive, holding your foot on the brake, and giving it just a LITTLE throttle to bring the RPMs up off normal idle some (at/near/not over 1000 RPM). Does the noise remain or disappear?

DISAPPEARS

Recorded a video & trying to get it on you tube.

Your replies point to an exhaust vibration issue. (good news for you - probably nothing serious).

The C5 commonly suffered from the same thing, although mine never had this trouble (though I would never hear it on my car even if it was), am not sure of the real fix.

Hopefully you can reply to this reply, as I've done nothing on the other end to change things...


:cheers:

Talked to Johnny (Posse Peep). Him and a Josh(Resurrection Auto/Vette Mech) said the same thing along the same lines with your diagnoses. We are gonna put it on the lift this afternoon to try and find the problem. :cheers:

:squirrelrun: