What Causes Severe Engine Vibration When Turning on the Car's Air Conditioning?

[VanessaMarie]

There are two main reasons for severe engine vibration when turning on the car's air conditioning. Below is a detailed explanation of these two causes: 1. Spark Plug Carbon Buildup: After a period of use, carbon deposits can accumulate on the spark plugs. If not cleaned in time, this will reduce the engine's torque output, leading to vibration when the air conditioning is turned on. 2. Throttle Body Carbon Buildup: When the air conditioning is turned on, the engine load suddenly increases, and the throttle valve opens wider. At this point, the issue of dirt buildup is magnified. If the throttle valve is stuck or fails to open to the proper position, it restricts the air intake, thereby reducing the engine's power and ultimately causing engine vibration.