i have a metalic noise

[shepsciderunion]

HI, This is my first time on a forum !
I have a 2004 Audi A8 LWB and i have a constant metalic sounding noise when the car is moving, itstops when the car stops.
it sounds like wheel bearing noise but i have had all 4 wheel bearings replaced, i thought it might be front pads and discs but i have had those replaced and the noise persists.
i am not sure wether it is engine based or comes from elsewhere, does anybody have any idea what it could be ?
Thank you in advance !

[towcestervag]

you need to get someone to listen to noise really?
have a look at the disc back plates
check for stones caught behind the caliper
after that it could be more serious ie transmission?

[hibberd]

is it an automatic or manual gearbox?

[shepsciderunion]

Hi, it is an automatic gearbox thanks

[hibberd]

if you want to split the sound to try to locate it, whilst driving switch from full auto to the hand selection and raise or drop a gear here and see if this afters the tone at all. If it doesnt then my mind would think its drive train related after the final box output shaft. You have no handbrake that you can apply by hand so its not possible to see if its front brake or rear brake related. Try checking and raising the tyre pressures firstly at the back and then at the front. The quattro is quiet noisy when tyres wear or tyre pressures differ. I was suprised when I had my winter tyres (new set) fitted how that altered the sound in the car. Also have the differentials oil changed. If none of this alter it my only other possibile actions would be to check the heatshields on, as well as the exhaust box to make sure its not a baffle plate in the exhaust and then change the gearbox oil.