The water temperature of the Ruifeng car reached 9 degrees, and the engine compartment made a scoffing sound, and the water temperature dropped and then slowly disappeared. What happened?

hello! The coolant is boiling! There may be several reasons for the high water temperature. 1. The cooling fan does not turn. The cooling fan may be controlled by a temperature control switch; It may also be controlled by a water temperature sensor. 2. Insufficient cooling medium. (1) antifreeze: high-end cars are required to be filled with antifreeze all year round; ② Water or distilled water: temporary substitution; ③ Water tank cover leaks. 3. The thermostat is damaged. (1) If you want to remove the thermostat, you should plug the small circulation at this time, so as to ensure that the coolant is completely dissipated by the water tank; (2) when installing a new thermostat, attention should be paid to the water hole, such as Santana, there is no water hole. At this time, a hole should be drilled with a 6mm drill. One function is for marking; Another function is that when the car is heating up, the temperature difference between the two sides of the thermostat will be generated, so that the thermostat can be opened accurately with the water temperature. 4. The water tank is blocked. ① External blockage should be removed by water or gas; (2) Internal blockage will affect the circulation of cooling liquid and generate pressure at the same time. At this time, there will be two results, one is that the water tank leaks, and the other is that the water temperature is particularly high when driving at high speed. 5. Pump failure. ① The timing belt is broken due to slipping or sticking of the impeller; ② Impeller deformation. 6. Cylinder erosion. (1) The combustion chamber collides with the waterway, which will drain water or discharge white smoke from the drainage pipe, resulting in frequent water shortage in the water tank; (2) the water channel collides with the oil channel (the oil is white with water); (3) The collision of water channel and water channel causes bad heat dissipation of cylinder block, especially at high speed; ④ Waterway blockage.