What Causes Severe Engine Vibration When the Car Air Conditioner is On?

[AnnaMarie]

Carbon buildup on spark plugs, carbon deposits in the throttle body, or deformed fans and loose screws can all cause engine vibration when the car air conditioner is on. Specific reasons are as follows: 1. Throttle body malfunction: When the throttle body fails, the vehicle may exhibit symptoms such as engine vibration, unstable idling, weak acceleration, and difficulty starting when cold. In this case, the throttle body should be thoroughly cleaned, especially removing any oil sludge attached to it. If the throttle body is structurally damaged, it should be replaced promptly. 2. Throttle position sensor issues: When the throttle pedal malfunctions, the vehicle may show symptoms like weak acceleration, severe jerking, or unresponsiveness to throttle input. In such cases, the throttle position sensor should be inspected, and it's advisable to use high-quality fuel regularly. After repairs, ensure to clear any fault codes promptly; otherwise, it may cause memory confusion in the vehicle's electronic system, leading to unnecessary issues later on.