What Causes the Fluctuation of the Temperature Gauge?
1 Answers
The fluctuation of the temperature gauge may be caused by a faulty temperature sensor, a damaged thermostat, or a cooling system malfunction. Faulty Temperature Sensor: The temperature sensor is installed on the water jacket of the engine block or cylinder head, directly contacting the coolant to measure the engine's coolant 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 car's temperature gauge, along with difficulties in cold starts and acceleration. Damaged Thermostat: The thermostat automatically adjusts the amount of coolant entering the radiator based on the coolant temperature, altering the circulation range to regulate the cooling system's heat dissipation capacity and ensure the engine operates within the appropriate temperature range. You can check the thermostat by feeling the temperature difference between its inlet and outlet. A damaged thermostat can disrupt the engine's normal operating temperature, leading to an unstable temperature gauge. Cooling System Malfunction: Leaks in the engine cooling system or a failing water pump can also cause the coolant temperature to fluctuate. Solutions: If the temperature fluctuation is due to a faulty sensor, it is often caused by a quality issue with the sensor. Disconnecting the battery for initialization can help determine if it's a temporary fault. If not, the sensor should be replaced promptly. If the thermistor in the thermostat degrades, it may not open at low temperatures but only at high temperatures, causing the temperature gauge to fluctuate. The thermostat should be removed and tested in a heater to confirm if it is damaged. If the issue lies in the cooling system, the engine and water pump should be inspected and repaired immediately.
