Bad vibrations?

[IROC-Z]

My Camaro makes what I can only describe as a resonating sound, almost a loud buzzing, that seems to come from under the car. It generally only seems to occur when the car is cold and only when first moving off from a standstill. Once up to temperature and on the road and even moving off from traffic lights etc it doesn’t seem to do it.

It also only seems to make the noise when I have the throttle in a certain position, if I accelerate hard it doesn’t do it (at least, I can’t hear it then) but it does if I move off at a sensible pace. I discovered the other day I can make the resonating sound stop if I alter the pressure on the throttle.

My only thoughts are a loose exhaust component or the transmission mounts which I believe are a weak point. Has anyone got any suggestions please?

[Motown Junk]

Sounds like exhaust to me (mine more clonks against suspension when cold, it's all very close on clearance).

[chevy-stu]

I think you've guessed right, exhaust or trans mount. Get it up on a ramp and have a good shake of everything..

[IROC-Z]

Thanks chaps, looks like I'll be getting the trolley jack out this weekend (again)

[LuS1fer]

On 3rd gens the exhaust runs very close to the passenger side sill (it rusts behind it) so I would check the trans mount (rubber often shears) and the exhaust mountings.