For the 1st half hour of using the aircon i get a hiss/click sound every 2-3 mins, after half hourish it stops! I had a new belt fitted at last service. The car is coming upto 90k and not had anything done to the aircon as it still works fine. Anyone had this problem? or know how to fix?
Thanks Tim.

 

Try getting the pressures tested to see if it's low on gas.