It's not necessarily the water temperature sensor. The water temperature is high in the following cases:
1: Check whether the water tank leaks, open the water tank, see if the water level is below MIN, if the water level is very low, it is likely to leak. Add water, open the exhaust screw near the engine to exhaust, check the leak point. There is gas in the tank will also cause high water temperature. Water leakage is generally cool car leakage, so to check after the hot car is cool, pay attention to see whether there is a leak in the warm air pipe joint leading to the driver's cabin, and look at the ground under the car when the water leakage is large in the morning. If there is no leakage point, but the water is gradually lower than the lowest point after a week or half a month or so, there is also a possibility that the cylinder pad is bare, and the water seeped into the engine and consumed. Open the oil filling port to see if there is white foam and bubbles, see if there is oil on the tank cover, and see if there is white water on the oil gauge. If there is, water is seeping in. Need to replace cylinder pad.
2: Change the water temperature sensor. If you do not open the pot, just show high water temperature, it may be caused by inaccurate water temperature sensor. Change the water temperature sensor.
3: Change the thermostat. The thermostat can not be opened, resulting in no circulation of hot and cold water, after the water temperature reaches 90 degrees, open the cabin cover to touch the water pipe near the engine hot (be careful), the water tank is not hot, that is, there is no circulation of water. It's hot on both sides. Otherwise replace the thermostat.
4: Change the water pump. The pump is the most expensive, so replace it last. Car for a long time, the fan blade of the pump is bad or off or blocked, I have personally seen my car's pump inside stranded a lot of rubber strip like things, the pump is not working well, can not let the water circulation, resulting in a rapid rise in water temperature. This will require a replacement of the pump.
If there is no part damage, it is generally good to replace the sealing rubber ring.