Has anyone experienced any noise from the diesel engine linked to the revs that can only be described as sounding like a cricket under the bonnet that gets louder on acceleration but goes away when the aircon is switched on for a short period of time and is also intermittent. This is my Second superb combi that has developed this same problem that the dealer thinks might be the high pressure diesel pump breaking down. Has anyone experience any similar problems with engine noise or diesel pum