How to Test if a Thermostat is Good or Bad?
2 Answers
Remove the thermostat from the engine, clean it, and then heat it in hot water. Use a thermometer with a range of 100°C to measure the temperature. According to the specified temperature at which the thermostat valve opens or the side valve closes, check whether its performance is good and whether it works reliably. Information about the thermostat is as follows: 1. The thermostat is a valve that controls the flow path of the coolant. It is an automatic temperature-regulating device, usually containing a temperature-sensing component, which opens or closes the flow of air, gas, or liquid through thermal expansion or contraction. 2. The function of the thermostat is to prevent the engine from becoming too cold. After the engine is operating normally, if there is no thermostat when driving at high speed in winter, the engine temperature may be too low. At this time, the engine needs to temporarily stop the water circulation to ensure that the engine temperature does not become too low.
I often remove the thermostat. Just prepare gloves and a pot of cold water. After removing it, boil it in cold water while inserting a thermometer to monitor. It's normal when the valve starts opening around 85°C. If the valve remains tightly closed even when the water boils, or if it leaks when closed in cold water, the thermostat is definitely broken. Avoid letting it touch the bottom of the pot during boiling, as it can affect the results.
