Ford garage said it was probably a radiator blockage and they needed to keep it two days, take radiator off and send it to a specialist radiator company to get it pressure tested. Reminded them it was a brand new radiator just fitted. Said it could still be blocked. Did not agree with this diagnosis so arranged to take it to a garage recommended by a mechanic who had previously worked there and rated them highly.Last resort time. Took it there today got aphone call to say it is sorted!!!!!!!!!!
Not actually overheating, PCM needed recalibration by Ford garage. Collecting car tomorrow so hope problem now finally solved.