What Causes the Engine to Be Very Hot While the Temperature Gauge Shows Normal?
2 Answers
It may be caused by a malfunctioning temperature gauge or insufficient coolant. Below is relevant information about the car temperature gauge: 1. Structure of the temperature gauge: Its sensor is a thermistor-type sensor, fixed with threads on the engine cooling water channel. The thermistor determines the current flowing through the coil winding of the temperature gauge, thereby driving the pointer to swing. 2. Introduction to the temperature gauge: The temperature gauge is an instrument that displays the temperature of the cooling water, with the unit being ℃ (degrees Celsius). In the past, tap water was used as the cooling water for car engines, but now many car engine cooling systems use specialized coolant, hence it is also called the coolant temperature gauge. The temperature gauge can also be indicated by a warning light; when the temperature warning light is on, it indicates that the temperature is too high.
I've encountered the situation where the temperature gauge shows normal but the engine overheats several times. The most likely culprit is a faulty coolant temperature sensor, which is located near the water pipe on the engine block and responsible for collecting temperature data. If the sensor signal is distorted, even when the actual temperature is alarmingly high, the dashboard will still display normal readings. Additionally, it's important to check whether the thermostat is stuck in the closed position, as this will cause the coolant to only circulate within the engine's small loop, preventing it from flowing to the radiator for cooling. The cooling fan is another key component to inspect—burnt relays or poor wiring connections can cause the fan to stop working. I remember when helping a friend repair their car last time, we found that rusted water pump impellers led to poor water flow, which also caused localized overheating. Finally, I'd like to remind everyone: if you encounter this situation, never force the car to keep running. High temperatures can warp and ruin the cylinder head gasket. The smart move is to pull over, park by the roadside, and open the hood to let the engine cool down.
