I was looking for a rattle under the bonnet yesterday and I can see one of the pulleys the serpentine belt runs round has lots of play in it. By process of elimination it is not the PS pump, alternator, water pump, AC pump or crank so what does that leave? It's one of the larger pulleys, right in the middle of the engine. If somebody has belt routing diagram for a straight 6 W211 E320 CDI then I would be grateful. Many thanks.