UKPassats

hi, this started recently after a session on the motorway, this car is used as a 10 mile daily commute. any way, this is noticeable when the engine is started and in neutral. noise increases as engine revs increase. a dull drone .. tried running without belts on, noise disappears, tried a new alternator, aux belt tensioner.

been to three different garages who cant pinpoint it from a road test. one said is the gearbox.

any feedback would be great

thanks