Don't turn off the engine immediately after finding that the water temperature is too high, because there are many reasons for the high water temperature, but there is probably only one fault at a time. Turning off other functions will cause the water temperature to be too high and damage the engine. The correct way is to park at idle speed, open the hood, turn on the warm air, dissipate heat as soon as possible, and stop in a cool place at the same time.
Next, check whether the coolant is sufficient. It may be that the owner forgot to add it in time. Choose products of the same brand and model when adding coolant, otherwise the antifreeze may fail due to chemical reactions caused by different components.
Then check whether the cooling fan is working properly. Failure will lead to untimely heat dissipation during high-speed operation, resulting in an increase in the temperature of antifreeze. If the fan gets stuck or burns out, it can be solved by itself. If it is a wiring problem, it needs professional maintenance.
The function of automobile water tank is to dissipate excess heat in the engine and keep the engine running at normal temperature. The water tank is the heat exchanger of water-cooled engine, and the normal working temperature of the engine is maintained by air convection cooling. When the cooling water in the water tank boils and expands due to high temperature, and the pressure exceeds the set value, the water tank cover will overflow and release the pressure to prevent the cooling water from decreasing and the cooling system pipeline from bursting.
When driving at ordinary times, pay attention to whether the pointer of the engine cooling water thermometer on the dashboard is normal. Other faults, such as engine cooling fan fault, may lead to the increase of cooling water temperature or the leakage of cooling system pipeline, and may also lead to the decrease of cooling water. Pay attention to whether the cooling water reduction amount and cycle are normal before adding distilled water.