my 1.3 doblo cargo is 4 yrs old and done 20,000 mls,fiat have just wrote to me and said the belt should be changed at 4 yrs old whatever the milage is due to it deteriorates with age.quoted me £180.is this right or are they taking the p**s.

Probably correct. Belts deteriorate with time as well as with usage. At your rate of mileage it will take you nine years to get to the 50,000, or whatever the recommended change interval is, and this would definitely be too long to go with any belt system on the car.

Wait and see what the others say though. I had mine done at 50,000 and 4.5 years.

However, I have the 1.9, which has a belt cam. Surely the 1.3 Diesel has a chain?

Are we talking cam belt or auxiliary belt here?