Does idling the car with the heater on cause damage to the vehicle?
3 Answers
Idling the car with the heater on does not cause damage to the vehicle as long as the engine reaches its normal operating temperature. However, if the heater is turned on while the engine is still cold and has not reached its normal operating temperature, it can slow down the engine's warming process, leading to increased fuel consumption. Nevertheless, this does not harm the car. Below is some relevant information: 1. The fuel consumption when using the heater during idling depends on the car's displacement and engine tuning. For household cars, idling with the heater on for one hour consumes approximately 1 to 2 liters of fuel, though this may vary depending on the car model. 2. While idling with the heater on does not cause serious damage to the car, it can affect the passengers inside. Since the fuel does not burn completely during idling, carbon monoxide is produced. If the windows are not opened, the concentration of carbon monoxide inside the car can gradually increase, potentially leading to carbon monoxide poisoning for the passengers.
As an auto mechanic, whether idling with the heater on is harmful depends on the situation. Turning on the heater immediately after starting the engine is definitely bad for the car because the engine is still cold. Forcing the fan to cool it down makes it harder for the coolant to warm up, not only increasing fuel consumption but also accelerating engine wear. However, if you turn on the heater after the coolant has reached normal operating temperature, it won’t harm the car since the heater uses the engine’s own heat. That said, I must warn you that prolonged idling in place can easily lead to carbon buildup, especially around the intake valves, and it’s also very fuel-intensive. Additionally, the battery charges slowly at idle, and running the blower consumes even more power—doing this frequently can shorten the battery’s lifespan. If you need to warm up the car for an extended period, I recommend driving it around for a few minutes every half hour to clear carbon deposits and recharge the battery.
A friend asked me about this recently! Having driven for fifteen years, I find sitting in a freezing car in winter the most annoying. If the temperature gauge hasn't reached the middle mark, don't rush to turn on the heater. Otherwise, not only will cold air blow out of the vents, but the engine will also have to work extra hard to heat up, causing fuel consumption to skyrocket. Once the water temperature is normal, idling to keep warm is completely fine—I often do this when driving my kids to tutoring. However, pay attention to two details: first, don't leave the AC button on, as it's for cooling and just wastes fuel; second, after keeping the windows closed for half an hour, crack one open for ventilation, or the windshield will fog up. As for carbon buildup, doing it occasionally won't cause issues, but my neighbor, a delivery guy, idled with the heater on for three hours every day, and later his engine shook like a tractor.
