Need a bit of help, just been out in the vectra.

Driving nice and steady no problems, but under heavy acceleration i'm getting this funny noise from under the bonnet, its really difficult to pin point where the noise is coming from.

Makes no difference whether in gear or stand still, and the noise doesn't speed up as i rev or speed up, just gets louder.

Its a Vectra Dti 2003.

I bets its going to expensive!! Just payed for a new master clutch servo.