I have a 2001 1.9 TD Zetec (115ps) Galaxy It has a metallic whirring, whooshing noise when accelerating. It happens when accelerating at any speed, in any gear. the noise is gradually worse as I accelerate harder. The noise stops when I ease off the accelerator. The noise nevers happen when I am at standstill, when idling or reving the engine. It does not happen when driving at a constant speed. There is never any smoke from it, it doesnt seem to lack power due to the noise (although I have just bought it so I don't know how it was before). Any ideas about possible causes? Many thanks!!