Old belt was very worn all ribs cracked and bits missing so put on new dayco fine for 200 miles then the squeaking started done the penny trick bliss for a short while the it was back have cleaned the belt and all pulleys but the only way I can get it to stop was by refitting the old worn belt which isn't going to last forever. If I put a little water onto the ribbed part of the belt it shuts up for a few seconds.