Any engine whether it be a car engine or truck engine, if it is liquid cooled it will have a thermostat. A thermostat controls the temperature of the coolant travelling from the radiator to the engine. Once the engine reaches it’s operating temperature generally around 95 degrees celsius the thermostat opens to allow the cool water from the radiator to cool the engine.
Trouble shoot an overheating engine
Step1: Check the coolant level in the expansion tank and make sure water is in the radiator by removing the radiator cap. Make sure the engine is off and has cooled down before opening the radiator cap.
Step2: Make sure there is no air in the system. If you find air bubbles in the system it can cause the coolant from not circulating properly. Run the engine until all bubbles have disappeared and top up regularly with coolant.
Step3: Make sure the radiator fans are spinning. Run the car to operating temperature and ensure the fans kick in and spin.
Step4: Test the fan motor. This is the electric motor that turns the fan blades.
Step5: Check the serpentine belt is connected as this turns the water pump motor.
Step6: Check for leaks. Firstly check under the cars engine on the floor. However small leaks do not leave a puddle on the ground. Check for any leaks around the rubber hoses connecting the radiator to the engine.
Step7: Check the thermostat. When a thermostat goes bad it will either be in the open or closed state. If it get stuck in the closed state the coolant will not circulate properly.