What are the symptoms of a faulty car temperature sensor?
3 Answers
Here are the symptoms of a faulty car temperature sensor: 1. The engine may overheat, and a yellow coolant temperature warning light will appear on the dashboard to alert the driver for inspection. When the car temperature sensor is damaged, it must be repaired promptly to prevent potential safety hazards during vehicle operation. 2. The car may experience difficulty starting when cold, as the system incorrectly determines that the engine oil and coolant temperatures are too low, preventing normal operation and making the engine hard to start. The car temperature sensor controls the temperature of the engine oil and coolant, thereby helping the engine run more efficiently.
A couple of days ago, my car's coolant temperature sensor failed, and I noticed the temperature gauge kept fluctuating. Sometimes it would suddenly spike into the red zone, triggering the engine warning light. The most annoying part was the severe shaking during cold starts—it felt like the engine wasn't getting enough fuel, with unstable RPMs and a noticeable lack of power. The cooling fan also acted erratically, sometimes spinning aggressively and other times not running at all, causing the coolant temperature to swing between overheating and normal. The A/C performance became inconsistent too, making the cabin unbearably hot in summer. Fuel consumption increased significantly—previously, a full tank could cover 500 km, but now it barely reaches 400+. The mechanic explained that the faulty sensor caused the ECU to miscalculate fuel injection, leading to excessive fueling. If left unrepaired, engine overheating could shorten its lifespan or even blow the head gasket. It's advisable to regularly inspect the cooling system to avoid breakdowns on the road.
I've experienced sensor failures, and the symptoms are quite obvious: the coolant temperature gauge shows inaccurate readings, often stuck at low or high positions; the engine warning light stays on, and the car is hard to start, especially in cold weather, with rough operation after ignition; the fan control system malfunctions, failing to activate when the coolant temperature is too high, which can easily lead to overheating; fuel consumption spikes by more than 10%, accompanied by a noticeable drop in power; and the cabin temperature regulation goes haywire, with the AC failing to cool or blowing air abnormally. All these issues stem from incorrect sensor signals, causing the ECU to misjudge the temperature and improperly adjust fuel injection and fan speed. Early detection can save you some money, but if left unattended, it may damage the engine or sensor wiring harness, doubling the repair costs. The key is to use a multimeter to test the sensor's resistance and replace it immediately if any abnormalities are found.
