Why causes a car to boil over after shutdown?

Answer 1

It is running hotter than it should. At shutdown, the temperature will go up and the engine will boil over. Engines today can have an operating temperature of as high as 265 Degrees Fahrenheit. When they are under pressure the coolant will not boil. Release the pressure and they boil over. You need to check a few things. Replace the radiator cap and see if that helps. It may not be holding the pressure. If so, that was probably the problem. If not, replace the thermostat and flush the system. A good thermostat will be ruined by overheating. Other possible causes of overheating are a bad fan or an electric fan that does not continue to run at shutdown. Loose belt, that is not turning the pump properly, exhaust back pressure due to a clogged converter, dragging brakes, and an engine over advanced in timing. answer generally if coolant boils over after shutdown, u have to much coolant in system wait till car is cooled down then check coolant level in over-flow tank there should be 2 marks one says cold level ,1 says hot level when car is cold make sure it is at cold level and not above