What Causes the Temperature Gauge to Fluctuate?
1 Answers
The fluctuation in coolant temperature may be caused by a faulty temperature sensor, a damaged thermostat, or a cooling system malfunction. Faulty Temperature Sensor: The temperature sensor is installed in the water jacket of the engine block or cylinder head, directly contacting the coolant to measure its temperature. If the sensor fails or malfunctions, the engine ECU will detect an unreliable output signal and intervene by using a substitute value to protect the engine. This can result in unstable readings on the temperature gauge, along with symptoms like difficulty starting a cold engine or poor acceleration. Damaged Thermostat: The thermostat automatically adjusts the flow of coolant into the radiator based on temperature, regulating the cooling system's efficiency to maintain the engine within an optimal temperature range. You can check the thermostat by feeling the temperature difference between its inlet and outlet. A faulty thermostat can disrupt the engine's operating temperature, causing the gauge to fluctuate. Cooling System Malfunction: Issues such as leaks in the engine cooling system or a failing water pump can also lead to erratic coolant temperature readings. Solutions: If the temperature fluctuations are due to a faulty sensor, first disconnect the battery to reset the system and check if it's a temporary issue. If the problem persists, replace the sensor promptly. If the thermostat's thermistor performance degrades, it may fail to open at low temperatures and only open at high temperatures, causing temperature fluctuations. Remove the thermostat and test it in a heating device to confirm if it's damaged. For cooling system issues, inspect and repair the engine and water pump as soon as possible.
