What are the issues with idling the car and turning on the air conditioning?

[Carmen]

Idling with the air conditioning on can cause certain damage to the vehicle and wear to the engine, potentially requiring shorter maintenance intervals. If the engine speed is too low to support the air conditioning, incomplete combustion may occur, leading to carbon buildup. Additionally, idling with the air conditioning on can result in poor system cooling, making it easy for the engine to overheat. Precautions for using car air conditioning are as follows: 1. Note 1: The refrigerant continuously expands and absorbs heat in the evaporator, cooling it. The cooled evaporator then cools the air blown by the fan, allowing the car's air conditioning vents to blow cold air. 2. Note 2: The refrigerant used in car air conditioning is R134a. The car air conditioning system requires regular refrigerant top-ups. Prolonged failure to add refrigerant can lead to reduced cooling efficiency and slower cooling speeds. 3. Note 3: Regular cleaning of the car air conditioning system is essential. Otherwise, bacteria can proliferate inside the system. When cleaning the air conditioning or adding refrigerant, always visit a professional service center where experts can perform the task using specialized equipment.

[OSerenity]

Last time I idled with the A/C on for half an hour, and my fuel gauge dropped a whole notch – what a pain! Prolonged idling with A/C forces the engine to operate inefficiently, not only causing fuel consumption to skyrocket but also leading to carbon buildup in the combustion chamber. Once at the repair shop, the mechanic shook his head while pointing at those black deposits on the throttle valve. What’s worse, the air quality inside the car keeps deteriorating, especially when exhaust fumes seep in during traffic jams – even using the fresh air mode makes my throat uncomfortable. Sleeping in a parked car with A/C on in summer is even riskier; a friend mentioned his coworker nearly got hospitalized from carbon monoxide poisoning. Now I limit A/C idling to 10 minutes max – saves fuel and gives peace of mind.

[Mockingjay]

As a father, I'm particularly cautious about idling with the AC on. Last year when taking my kid out, we idled with AC at a service area and the child almost vomited from dizziness - that's when I learned about rising carbon monoxide levels. Now I always crack open windows for ventilation when parked with AC, and never exceed 20 minutes. The car suffers too - last time the battery drained inexplicably, and the mechanic said it was from excessive idling with AC. Not to mention carbon buildup - neighbor Lao Wang's SUV needed major engine repairs after just 3 years from frequent AC idling. If waiting briefly, carrying water is more practical than running AC.

[Ursula]

The most obvious issue with idling with the air conditioning on is environmental pollution! When the engine is idling, combustion is incomplete, leading to black smoke from the exhaust pipe and emissions that exceed standards by at least twofold. In our neighborhood group, people complain daily about the smell of exhaust in the underground garage. Vehicle damage also accelerates—my cousin's Japanese car, operated this way for three years, had its oxygen sensor ruined. During peak hours in the city, idling with the AC on forces the engine to run at low RPM for extended periods, causing severe carbon buildup, necessitating regular throttle body cleaning. The most baffling part is some people leave the AC on overnight to sleep, completely disregarding the danger of exhaust gas backflow.

[VanPhoebe]

I've seen too many cases where idling with the AC on damages the battery. Last time, a lady came in with a car that wouldn't start—the battery voltage was only 8V. Turns out she'd been sitting in her car with the AC on for half an hour every day after work while waiting for her child. At idle, the alternator can't keep up with the AC's full load, causing the battery to discharge deeply. There's also the cooling issue—running the AC while stationary in summer makes the cooling fan spin like crazy, showing how hard the cooling system is working. Older cars' water pumps and fans are especially prone to failure. Nowadays, I advise customers to drive around a bit if they want to use the AC—it's much better for the car.

[VanIsabel]

Having driven a taxi for over a decade, nothing annoys me more than passengers asking to keep the engine idling with AC on while waiting. The most obvious impact is watching the fuel gauge drop—over two hours can burn more than a liter of gas, costing me dozens of yuan a day. The mechanical wear is even sneakier: prolonged low-RPM idling clogs fuel injectors like clockwork, forcing me to clean them monthly. The AC compressor’s constant cycling at idle also brutalizes the clutch—once, it seized entirely during a highway rest stop, leaving me with no cooling. Now I set ground rules: engine off if waiting exceeds five minutes. Saves the planet and my car.