Hi i have a Ford Fiesta 2000 MK4 1.25 zetec LX car. and it keeps overheating. the fans in the car are working (hot + cold). I have had RAC out and they have said the head is fine, i have changed the Thermostat and the tempature clip. When i am driving the engine will over heat and the fans in the engine bay will come on. I have done all the obvious fixes but its still over heating. What shall i do???