What are the causes of engine idle vibration?
2 Answers
The causes of engine idle vibration are: 1. The vehicle's ignition system has malfunctioned; 2. Components in the ignition system have become loose; 3. Severe carbon buildup in the engine; 4. Aging of engine components; 5. Excessive carbon buildup in the throttle; 6. The air filter has not been replaced in time; 7. Excessive carbon buildup in the fuel injectors; 8. Issues with the ignition system; 9. Unstable oil pressure. Engine idle is not a speed but a working condition. When the engine runs without load, it is called idling. When the engine is running and the accelerator pedal is completely released, the engine is in an idle state. The engine speed during idling is called the idle speed, which can be adjusted by modifying the throttle opening size, among other methods.
Last time my car shook like a vibrating phone while waiting at a red light. The veteran mechanic said it was caused by worn engine mounts. These rubber components harden and crack over time, just like when sneaker soles wear thin and lose their cushioning effect. Carbon buildup is another common issue—dirty throttle bodies and fuel injectors can cause unstable air intake, especially with frequent short trips that promote carbon deposits. Check if the spark plug gaps are too wide; last time I replaced mine with iridium plugs, only to find after three months of shaking that they were the wrong model. Aging ignition coils or poor fuel quality can also cause intermittent misfires, accompanied by a sputtering exhaust sound. Oh, and if the shaking worsens with the AC on, it’s likely due to compressor load affecting engine RPM fluctuations.
