Is my exhaust blowing?

[astraman]

When pulling away in my astra especially on a gradient or hill etc i can hear a rumbling from under bonnet.This noise stays the same when i am holding the car at biting point on a hill then diappears as the car accelerates on an even surface or decellerates also on an even surface.My cousin says i have a small hole in my exhaust which due to load pressure is noticeable especially holding the car at biting point on a hill.Is this correct or is there another possibility?

[stanleyman]

You might have a blowing exhaust and this would be noticable as you accelerate as well but as the engine is moving against the mounts in this situation it could be anything touching or straining including the exhaust.

[markja]

the clutch thrust bearing sometimes makes a noise when the clutch is pushed down, is this a possibility? this would happen on the flat also though.