In the range 1700/2200rpm going up or down there is a noise like a slipping belt but not as loud or as high pitched. It seems to occur more in the colder weather although it is around most of the time. The car has been into main dealer 18 times (is 2009 with 41k on clock). It has had, new oil filters, air filters, fuel filters, tank clean, all new fuel lines, all new belts and goodnes only knows what else including a visit by head office technical expert all with no cure. Noise seems to come from right front area of car. Today into main dealer as in same rev range now have a 'tinny' sound and engine sounds very harsh when accelerating. First a test drive - oh says mechanic still got that old sound then. Agree new sound there- 1 hour in workshop sorry cant find any reason for it but agree its there as is the old sound. Any ideas anyone.