whinning

Hello lovely people:) My first time posting a question! Please some one tell me what to do. My beloved SL600 (2006, 50,000 miles) has a problem. After a few miles of driving it I hear an unusual whistle sound which I can only assume to be the turbo. After a few miles more, the car feels like it...

Hi all, i was wondering if anyone has had this problem: When accelerating up a hill the whinning stops, if i stop accelerating the noise comes back also when accelerating downhill over 60 it makes the same noise Any help would be much appreciated Regards Btw its the van has a...