My C220 D 2001 is making a noise at idle and the fan belt(Serpentine belt) is flapping up and down and cauing it to cut the fuel pipe which routes above it. I have replaced the pipe to get the car running again and also changed the water pump which was stiff and had play in it. If you just get the car above idle it runs lovely, the belt runs smoothly and the noise goes away. Could it be sonething like the pas pump or an EGR fault causing the rough idle? I initially thought that one off the accessories( alternator, water pump, pas pump etc had a high resistance and caused the belt to flap but they all seem fine. Tensioner also has plenty of strenghth in it and the new belt I fitted is nice and taught. Is this a common prob. Any help appreciated as pulling lots of hair out here.
Thanks.