Why does the car body shake when the air conditioner is turned on?
2 Answers
Car shaking when the air conditioner is on is generally caused by carbon buildup on spark plugs, carbon buildup on the throttle valve, or fan deformation or loose screws. Below is a detailed explanation of the reasons for car shaking when the air conditioner is on: 1. Carbon buildup on spark plugs: After a period of use, spark plugs will accumulate carbon deposits. If not cleaned in time, this can reduce the engine's torque output, leading to shaking when the air conditioner is turned on. Soak the spark plugs in a container with white vinegar for 2-3 hours, or 4-5 hours for severe cases. Then use a stiff brush to remove the carbon deposits. Clean them with gasoline and let them air dry naturally. 2. Carbon buildup on the throttle valve: When the air conditioner is turned on, the engine load suddenly increases, and the throttle valve opens wider. At this point, the issue of dirt is magnified, causing the throttle valve to stick or fail to open to the proper position, obstructing the air intake and reducing engine power, which eventually results in engine shaking. 3. Fan deformation or loose screws: Check if the shaking is caused by resonance when the fan operates after the air conditioner is turned on or if it's due to loose fan mounting screws causing vibration.
Last time I turned on the AC, the car body suddenly started shaking, feeling like the whole vehicle was wobbling. After inspection, I realized it was due to excessive engine load—the AC compressor requires extra power to start, and if the engine is old or has faulty components, shaking is likely. Common causes include worn spark plugs, faulty ignition coils, or loose engine mounts. Aging belts can also worsen the shaking. In my case, replacing the belt and spark plugs fixed the issue. Additionally, carbon buildup or fuel system problems shouldn’t be ignored, as they affect fuel efficiency and performance. I recommend regular engine maintenance, cleaning fuel injectors, and checking mount bolts. If left unaddressed, the shaking could damage other components and increase safety risks.
