What Causes Severe Vibration When the Air Conditioner is On?
2 Answers
Severe vibration when the air conditioner is on may be caused by a malfunctioning air conditioning speed-up device, carbon buildup in the throttle body, or a collapsed or damaged engine mount. Check if the air conditioning speed-up device is malfunctioning or broken. Normally, when the air conditioner is turned on, the idle speed should increase by 200 to 300 RPM. If this speed-up device is faulty, it will cause noticeable vibration. This speed-up device is essentially the idle speed solenoid valve, which might be stuck—cleaning it could resolve the issue. Carbon buildup in the throttle body can make the engine struggle to drive the compressor, leading to idle vibration. The throttle body should be cleaned, and if driving conditions are harsh, regular cleaning is recommended—preferably every 10,000 kilometers.
My vehicle has also experienced similar issues, where the body shakes particularly violently when the air conditioning is on. This is often caused by a sudden increase in engine load, especially noticeable in smaller displacement models. There might be underlying problems with the engine itself, such as excessive carbon buildup in the throttle body, aging spark plugs, or clogged fuel injectors, leading to unstable power output. Another common issue is the aging of engine mount rubber cushions. Over time, these rubber components harden and crack, losing their damping effect. When the air conditioning compressor starts, the engine bears additional load, making the shaking sensation particularly pronounced. It's recommended to first check the engine's operating condition and try cleaning the throttle body to see if it improves. If necessary, the condition of the engine mounts should also be inspected.
