Hi , i wonder if someone could assist or if anyone has had this before , i own a 2006 ford mondeo estate 1.8 duratec , so a month or so ago , i had my window down and whilst i was accelerating , there was like a chatter rattle noise coming from the driver side engine area , it doesnt happen when slowing down and there doesnt appear to be any noise of a rattle kind on idle , just the usual gentle tapping noises , i recently had the aux belt replaced and the mechanic checked all the pulleys on that side , so im at a loss at the min , it doesnt affect the car in any way , still starts and drives , just interested to find out what the noise is , can it be causing any damage and what the severity of the source is , thanks in advance