4.0 v8 1997 I've just tried bleeding the system again with the car at a angle. The car temperature gauge sat in the center. Car was ticking over for about 20 mins. Then the temperature went to the red with the light on. Car engine was not hot still had the expantion tank cap off so no pressure. But does have alot of pressure when the cap is on and taken for a drive. Any advise please. I can see the water flowing back into the tank. However radiator is Stone cold and the thermostat housing at the bottom of the radiator the water pipe is cold (from bottom of rad to thermostat) any ideas??? I've changed the temperature gauge and sensor. Also changed the radiator thermostats and expantion tank cap also flushed the system and new coolent put in but still the same problem. I don't know if there is a air lock as there is no bleeder valve. Can anyone shed some light on this for me please or no the best way to bleed the cooling system.