recently bought a rover 75,with a over heating problem,previous owner has had it pressure tested and found no head gasket leak,checked inside oil filler cap no "mayyonnaise" dipstick shows clean oil,and header bottle has clean water ,no oily sediment,it seems upon driving the car,under acceleration,whilst a cold airflow is being driven against temperature stay normal,it seems the temperature gauge rises to red light coming on and computer advising engine over heat,when moving again the temperature goes back to normal.
any one got any ideas to solve the problem, all ideas will be greatly appreciated

hammers_bob, February 2011

head gasket have you had a sniffer test done that's the first move, checks for exhaust in the water,
Mal

solo.cab, February 2011

yes coolant fan kicking in when getting hot

hammers_bob, February 2011

is your coolant fan kicking in when starting to get hot when idling

cdc, February 2011