How to check the car engine thermostat?
In the long-term use of the car, the thermostat will sometimes fail, causing the engine to be overheated or overcooled, the power will drop, and the fuel consumption will increase. Therefore, it is necessary to strengthen the on-board inspection of the thermostat.
(1) Inspection when the engine is just started.
Open the water tank cover, if the cooling water in the water tank is calm, it means that the thermostat is working normally.
- This is because when the water temperature is lower than 70°C, the expansion cylinder of the thermostat is in a shrinking state, and the main valve is closed;
- when the water temperature is higher than 80°C, the expansion cylinder expands, the main valve is gradually opened, and the circulation in the water tank starts to work.
- If the water temperature gauge indicates that it is below 70°C, and there is water flowing at the water inlet pipe of the water tank and the water temperature is slightly hot, it means that the main valve of the thermostat is not closed tightly, causing the cooling water to circulate prematurely.
(2) Inspection after the water temperature rises.
In the early stage of engine operation, the water temperature rises rapidly. When the water temperature rises to 80°C, the temperature rise rate slows down, indicating that the thermostat is working normally.
On the contrary, if the water temperature has been rising rapidly, and when the internal pressure reaches a certain level, the boiling water suddenly overflows, which indicates that the main valve has a long lag and suddenly opens. When the water temperature gauge indicates 70 to 80°C, open the water tank cover and the water discharge switch, and feel the water temperature with your hand. If there is water, it means that the thermostat is normal; Or there is very little water, indicating that the main valve of the thermostat cannot be opened.