What Causes Abnormal Idle Vibration When the Car Air Conditioner is On?

[ColeFitz]

Here is a detailed analysis of the specific reasons for abnormal idle vibration when the car air conditioner is on: 1. Severe engine carbon buildup: The most common cause of vibration is a dirty throttle body or excessive carbon deposits in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, making it difficult to start. The solution is to clean the fuel system and check if the idle control valve has carbon buildup, which should be cleaned. 2. Unstable fuel pressure: Check whether the fuel supply pressure and the intake pressure sensor are functioning properly. If the fuel pump supply pressure is abnormal or the intake pressure sensor values are incorrect or malfunctioning, it can cause body vibration. The solution is to check the fuel pressure and replace components if necessary. 3. Aging engine components: Car vibration is also related to worn engine mounts. Engine mounts are essentially the shock absorption system of the engine, responsible for absorbing minor vibrations during engine operation.