The most common problem is the low engine temperature. If the water temperature of the car does not reach 70 degrees, and it is very hot to touch the water tank with your hands, then this is the simplest problem, and the thermostat is broken.
The thermostat needs to be replaced. The following figure shows the appearance of various thermostats. Just buy one and change it according to the thermostat of the car. However, attention must be paid to the installation, and the periphery of the thermostat should be sealed to prevent water leakage. If you don't believe in paper mats, you can cut one from the waste inner tube of the car and put it on.
Extended data:
When the engine starts to run cold, if there is still cooling water flowing out of the water tank inlet pipe, it means that the thermostat main valve cannot be closed; When the engine cooling water temperature exceeds 70℃, there is no cooling water flowing out of the water tank inlet pipe, indicating that the main valve of the thermostat cannot be opened normally and needs maintenance. The thermostat in the vehicle can be checked as follows:
Inspection after engine starting: Open radiator filler cap. If the cooling water in the radiator is calm, it means that the thermostat works normally; Otherwise, the thermostat is not working properly. This is because when the water temperature is lower than 70℃, the expansion cylinder of the thermostat is in a contracting state and the main valve is closed. When the water temperature is higher than 80℃, the expansion cylinder expands, the main valve gradually opens, and the circulating water in the radiator begins to flow.
When the temperature indicated by the water thermometer is below 70℃, if there is water flowing through the water inlet pipe of the radiator and the water temperature is warmer, it means that the main valve of the thermostat is not closed tightly and the cooling water circulates prematurely.
Baidu encyclopedia-thermostat