What are the symptoms of a faulty vehicle temperature sensor?
2 Answers
Common symptoms of a faulty vehicle temperature sensor include abnormal signals. Below are specific symptoms for different types of faulty temperature sensors: 1. Intake Air Temperature Sensor: If the intake air temperature sensor malfunctions or fails, the engine cannot accurately calculate the fuel injection volume, resulting in an overly rich or lean air-fuel mixture. This can cause difficulties in starting, unstable idling, engine shaking, or black smoke emissions, affecting engine performance. 2. Coolant Temperature Sensor: A faulty or damaged coolant temperature sensor prevents the engine from properly regulating water temperature, leading to insufficient cooling. This may result in overheating ("boiling") or cylinder scoring. Symptoms include hard starting when cold, unstable idle, shaking, and poor acceleration. When the engine is hot, the malfunction indicator light may stay on, and the cooling fan may stop working. 3. Ambient Temperature Sensor Inspection: The ambient temperature sensor (also called outside air temperature sensor) is typically installed near the front bumper or grille. Its sensing element uses negative temperature coefficient thermistor technology. Testing methods for the ambient temperature sensor are similar to those for the coolant temperature sensor. Use a multimeter's resistance mode to measure its resistance value: normal resistance at room temperature should be 1.6-1.8KΩ (resistance increases as temperature decreases). If the measured resistance exceeds specified values, this indicates either an open circuit in the sensor wiring harness or poor connector contact, which can affect normal operation of the vehicle's air conditioning system. Further inspection or replacement is recommended in such cases.
I noticed the temperature gauge on the dashboard wasn't moving while driving, even though the engine was already warm—it still showed cold. Starting the car became difficult, the engine shook noticeably at idle, and fuel consumption inexplicably increased. The fan wasn't working, and I could hear the engine gurgling at red lights, making me worry about overheating. The air conditioning's cooling performance was poor, making summer drives uncomfortably stuffy. The check engine light stayed on, and a visit to the repair shop revealed a faulty temperature sensor. This sensor is responsible for informing the computer about the engine's temperature, which then adjusts the air-fuel mixture and controls the fan. Delaying repairs could lead to serious engine damage. I recommend checking the sensor during regular maintenance to prevent minor issues from turning into major problems.
