Cheers for the replies everyone, the fan is still running but the fuel consumption has picked up, did a run from Cambridge down to Exeter, 250 miles at a steady 70mph except for a legal 50 through the road works and it has still got over half a tank of diesel in it.

Tabetha...thanks for that, got it booked in for a full service etc so hopefully anything in the ECU will be picked up!!

AndyST......cheers for that, will check it out tomorrow morning!!

Thanks once again everyone for taking the time to reply.

Rick.