What causes severe shaking when the air conditioning is turned on?
3 Answers
The cause of severe shaking when the air conditioning is turned on is due to a seized air conditioning compressor. A seized compressor directly drags down the engine's RPM. When the engine control unit (ECU) detects this abnormality, it injects excessive fuel in an attempt to restore the engine to normal speed. The combination of the seized compressor and the ECU's response can cause severe engine shaking or even stalling. Other reasons for car shaking include: 1. Ignition system issues: If the car's ignition system malfunctions, it can lead to poor ignition system performance, weak spark plug firing, and other problems, resulting in unstable idle conditions. 2. Poor fuel quality: Research has found that most cases of 'idle' shaking and instability among domestic car owners are closely related to fuel quality. Poor fuel quality can damage engine performance, leading to idle shaking issues.
The car shakes badly when the AC is turned on. I've encountered this issue several times. It's mainly because the AC compressor increases the engine's load after starting, like an old engine carrying extra weight, causing unstable RPM and shaking. Common causes include excessive engine carbon buildup restricting airflow, worn spark plugs with poor ignition, insufficient oil leading to poor lubrication, or a stuck AC compressor consuming extra power. My old car once had this issue due to aged spark plugs, and it improved significantly after replacement. A loose belt can also cause this—listen for unusual noises during inspection. Safety first; don't delay. Get it checked by a professional shop as soon as possible. Regular maintenance, like cleaning the throttle body, can prevent this. This problem not only affects driving comfort but may also lead to premature engine wear.
When I drove my friend's car before, the engine would shake violently when the AC was turned on, which was really annoying. The reason is usually that the increased suction from the compressor causes engine RPM fluctuations, especially when the car's idle is unstable to begin with. Common fault points include excessive cooling system load leading to voltage instability, aging or slipping drive belts increasing resistance, or a clogged air filter causing insufficient air intake. For a simple check, you can try listening to whether the compressor sounds normal when it starts and observing if the engine RPM gauge fluctuates significantly. Additional advice: regularly maintain battery health and replace belts periodically to reduce the risk of shaking. For a more economical approach, don't rush to replace parts—first, test whether the compressor pressure is normal. Long-term neglect can worsen engine wear, making repairs more expensive.
