Strange noise on my Series 3 is driving me mad!After about two miles from cold,a strange high pitched whine eminates from the engine bay on overrun only.It is related to engine speed directly,lasts about 15 secs in neutral on tickover,then disapears!May be related to a slight misfire.Both conditions go if i stop and start engine,but whine will reappear after about 30secs of driving.I have recently replaced alternator,and water pump and fan belt all ok.Would be very gratefull any suggestions!
