Thermostat general problems will lead to the main valve opens too late or too early.
If open too late will cause the engine overheating;
If open early, will make the engine preheating time extended, the engine temperature is too low, which affects performance.
In simple terms, is the performance after the thermostat failure is high or low temperature, water temperature, then, how to judge the thermostat failure?
1, check after the engine starting, open the cooling water tank and water flap, and see whether the water cooling tank of water flow phenomenon, if there is no water flow means thermostat has a foreign body damage or card to switch between the main valve.
2, check the engine work after a period of time, when the water thermometer instructions below 70 ℃, and see whether there is water flow tank radiator inlet line, if the hot water temperature, cooling water may be too early systemic circulation, the season that there might be a probe is the main valve closed lax fault;
When the water temperature higher than 80 ℃, through the tank cover to see if the water flow, if there is a fault, not flow thermostat needs replacement.
3, observe the water thermometer, see if water thermometer display abnormal, when the water temperature is below 80 ℃, see water thermometer, generally at the beginning of the engine operation, water temperature table pointer to rise soon.
And when the water temperature higher than 80 ℃, water temperature table pointer speed is slow, this suggests that the thermostat is normal.
If the water temperature has been increased quickly, especially when the tank pressure to a certain extent, suddenly boiling water overflow, this suggests that the main valve is binding or probe is failures.
4, with the hand feel the water temperature, the method of open water radiator cap and waterproof switch, with the hand to feel the temperature of the coolant, if hot, then normal thermostat;
If water inlet water temperature is low, the radiator water chamber inlet line without coolant flow, or flow rarely, suggests that there is something wrong with the thermostat main valve, shall promptly carry out repairs at this time.