What Causes Idle Vibration When the Air Conditioner is On?

[MacMalia]

Here are the specific reasons for idle vibration when the car's air conditioner is on: 1. Shock absorber system failure: The shock absorber system is mainly responsible for filtering the vibration of the engine during operation. If there is a problem with the shock absorber, these vibrations will be directly transmitted to the steering wheel and the cabin, affecting driving. When the engine is idling, turning on the electrical systems inside the car can also easily cause vibration. The engine increases its load due to the activation of electrical systems, leading to a drop in idle speed. To compensate for the vibration caused by the drop in idle speed, the engine will automatically increase the RPM. When turning on electrical systems, especially the air conditioner, the engine often experiences vibration. This vibration is likely caused by aging shock absorbers and requires timely replacement. 2. Unstable oil pressure: If the engine carbon deposits have been cleaned, the throttle body has been cleaned, and the oil pads have been replaced, but the car still vibrates, it is recommended to check the fuel supply pressure and the intake pressure sensor at a repair shop. If the fuel pump supply pressure is abnormal or the intake pressure sensor values are incorrect or malfunctioning, it can cause car vibration. 3. Cold start: The main reason for car vibration during a cold start is insufficient fuel combustion, resulting in insufficient power from the car. The ignition energy is relatively low, and during startup, when the temperature of the fuel and lubricating oil is low, more fuel is needed to meet the power demand. Over time, the electrode gap of the spark plug gradually increases, leading to a decrease in ignition energy and poor fuel atomization, which causes car vibration. In addition, aging ignition coils, aging high-voltage wires of the spark plugs, or leakage can also lead to a decrease in ignition energy.