Does idling the car with the heater on damage the vehicle?
3 Answers
Idling the car with the heater on can cause damage. When the engine is idling, incomplete fuel combustion produces carbon monoxide. If the windows remain closed, the concentration of carbon monoxide inside the vehicle will gradually increase, potentially leading to carbon monoxide poisoning for the occupants. Additionally, using the heater while idling slows down the engine's warm-up process. Below are the hazards of prolonged idling: Wear on components: During idling, oil pressure is lower, reducing the lubrication effectiveness of the engine oil and accelerating wear on internal engine parts. Idling also leads to incomplete fuel combustion, which can cause carbon buildup in the throttle body. Accelerated cylinder corrosion: When the coolant temperature drops below 60 degrees Celsius, combustion byproducts in the cylinders react chemically with the moisture in the coolant, forming acidic substances that accelerate cylinder corrosion.
I've been driving a taxi for ten years, often idling with the heater on in winter. The heater uses waste heat from the engine, unlike the air conditioning compressor which adds extra load. But there are two things to watch out for: First, prolonged idling with the heater on can cause carbon buildup, especially in stop-and-go city traffic where the engine doesn't burn fuel completely, leaving the exhaust pipe black inside. Second, in some older cars with aging batteries, running the blower can drain power too quickly—I've had the engine fail to start twice because of this. So now I limit it to half an hour at most, or drive a few kilometers instead. Also, always use it in open areas, otherwise exhaust fumes can accumulate dangerously.
Last time I went to the 4S shop for maintenance, I asked the mechanic this question. He said that there's basically no problem with new cars nowadays, as the heat for the warm air comes from the engine's cooling system. However, there are two potential issues: First, it consumes more fuel. Idling with the heater on burns half a liter more per hour than turning off the engine, and you can visibly see the fuel gauge dropping. Second, it puts a lot of strain on the battery. The blower is powered by electricity, especially in winter when the battery's performance declines. If you also have the radio on and are charging your phone, the car might suddenly stall. It's recommended not to use it for more than 20 minutes at a time and to open the engine hood for cooling during long-distance breaks.
