:sadlike, Yesterday i topped up my coolant level and stupidly drove around for about an hour without replacing the cap, i realised this after parking up and seeing water gush out from under the bonnet, i topped up the bottle, replaced the cap and carried on as normal. I let the car cool down for about an hour after driving it again, i now have a temp problem. If i run the car without the cap the temp will stay at 90, as soon as i replace the cap the car starts overheating, im only getting cold air from the heaters and only half of the pipes are getting hot, ive been told its a number of things can any1 help???!!! Does anyone know the correct procedure for bleeding the system??