Does idling with the air conditioning on damage the car?
2 Answers
Idling with the air conditioning on can damage the car. Keeping the engine idling while stationary increases fuel consumption, and prolonged idling accelerates carbon buildup. Over time, this can lead to symptoms such as rough idling, increased fuel consumption, and poor acceleration. Carbon buildup has the following harmful effects. 1. Carbon deposits in the fuel system can affect the injector's performance, leading to poor atomization and increased fuel consumption. 2. Carbon deposits on the pistons can disrupt the air-fuel mixture, reduce flame propagation efficiency, worsen emissions, and potentially cause engine knocking. 3. Carbon deposits on the intake valves can disrupt airflow, resulting in reduced power and lower engine performance. 4. Carbon deposits on the spark plugs can affect the breakdown voltage, disrupt ignition timing, and cause starting difficulties and engine vibration.
When repairing cars, we often see vehicles idling with the AC on for extended periods, which is indeed not very friendly to the engine. When the engine runs at low RPMs, incomplete gasoline combustion can easily lead to carbon buildup—similar to making you jog in place without moving forward, causing your joints to creak after a while. Especially in older cars, piston rings and valves are more prone to getting stuck due to carbon deposits. Another headache is that when the car is stationary, the radiator’s cooling efficiency drops, causing the water temperature to rise quietly. The electric fan spinning nonstop at high speed also increases the electrical load. It’s recommended not to exceed 30 minutes. If you really need to run the AC for a long time, try parking in a shaded area, shifting to N gear, and slightly increasing the RPM—this protects the engine and saves fuel.
