1: Check whether the water tank leaks. Open the water tank to see if the water level is lower than MIN. If the water level is very low, it is likely to be leaking. Add water, open the exhaust screw near the engine to exhaust, and check the water leakage point. The air in the water tank will also cause the water temperature to be too high. Water leakage is usually caused by a cold car. Check again after the hot car cools down, and pay attention to whether there is water leakage in the warm water pipe joint leading to the cab. There is a lot of water leakage in the morning, just look at the ground under the car. If there is no water leakage point, but the water gradually drops below the lowest point after being filled with water for one week or half a month, there is another possibility that the cylinder gasket is smashed and the water seeps into the engine and is consumed. Open the oil filler to see if there are bubbles and bubbles, see if there is oil on the water tank cover, and see if there are white water drops on the dipstick. If there is, water is seeping in. The cylinder gasket needs to be replaced.
2: Replace the water temperature sensor. Not boiling the pot just means that the water temperature is high, or it may be caused by the inaccurate water temperature sensor. Replace the water temperature sensor.
3: Change the thermostat. When the thermostat is not turned on, cold water and hot water will not circulate. When the water temperature reaches 90 degrees, open the hatch cover and touch the water pipe near the engine (be careful). If the water tank is not hot, it means that the water is not circulating. It's hot on both sides, otherwise the thermostat will be replaced.