What Causes Car Vibration When the Air Conditioner is On?

[Felix]

Car vibration when the air conditioner is on is caused by: 1. Carbon deposits on the spark plugs leading to reduced engine torque output; 2. Carbon buildup on the intake valves causing abnormal cylinder pressure, prompting the car's computer to detect cylinder misfire and automatically cut off fuel supply; 3. Using the wrong gasoline resulting in severe engine carbon deposits; 4. A dirty throttle body affecting engine operation. Solutions include: 1. Soaking the spark plugs in a container with white vinegar for 2 to 3 hours, scrubbing off the carbon deposits with a stiff brush, and then cleaning them with gasoline; 2. Driving at high speeds above 4000 RPM to burn off carbon deposits in the cylinders; 3. Choosing the appropriate gasoline based on the car's compression ratio; 4. Cleaning the throttle body.