What Causes the Car Body to Shake When the Air Conditioning is On?
2 Answers
Reasons for car body shaking when the air conditioning is on: The throttle body is dirty, which affects the engine. If the air conditioning is turned on at this time, it will increase the engine idle speed, causing the steering wheel to shake. It is recommended to go to a 4S shop to check the working condition of each cylinder and then clean the throttle body. After prolonged use of the car air conditioning, the air filter will accumulate dust, catkins, and other unknown dirt. These contaminants may also adhere to the condenser and radiator. When the cooling effect of the car air conditioning is poor, you can check if the air conditioning is dirty. After cleaning the air conditioning, see if the effect improves. If the accumulation of dirt is severe, replacement may be necessary.
I've encountered this issue many times where the car shakes when the AC is turned on. It's mainly because the AC compressor starts up, instantly increasing the engine load. If the engine mounts are loose or worn out, the vibration becomes particularly noticeable. Check the engine mounts—they often deform due to heat aging and need replacement if damaged. Ignition system issues can also be a culprit; unevenly worn spark plugs can lead to incomplete combustion, making the engine more prone to shaking under high load. Fuel supply problems shouldn’t be ignored either, such as clogged fuel injectors or insufficient fuel pump pressure, which become more apparent when the AC is on and RPM fluctuates. Belt issues are another factor—if the compressor belt is too loose or worn, the engine may slip, worsening the shaking. A quick check of the spark plugs and mounts is a simple and cost-effective first step. Don’t overlook these small details during regular maintenance—preventing issues is much better than breaking down on the road.
