What Causes Idle Vibration?
2 Answers
Causes and solutions for car vibration during idle are as follows: 1. Severe engine carbon buildup: The most common cause of car vibration is a dirty throttle body or excessive carbon deposits on the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making it difficult to start. In this situation, the engine will only start easily once the carbon deposits have absorbed enough gasoline. After starting, the gasoline adsorbed on the carbon deposits is then drawn into the combustion chamber by the engine's vacuum, enriching the air-fuel mixture. This fluctuation between lean and rich mixtures causes idle vibration after a cold start. 2. Ignition system issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or spark plugs can also lead to such symptoms. 3. Unstable fuel pressure: If you have already cleaned the engine carbon deposits, throttle body, and replaced the spark plugs but still experience idle vibration, it is recommended to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor can also cause car vibration.
Idle shaking means the car is stationary, and the engine shakes severely when the rpm is low. I remember encountering this issue when I first bought the car, mainly due to an unbalanced engine system. Common causes include aging or burnt spark plugs, leading to uneven ignition; excessive carbon buildup in the engine, affecting fuel combustion; or a dirty air flow meter, resulting in inaccurate signals. These are minor issues, but if ignored, fuel consumption may increase over time, and the engine could be more prone to damage. Once, I neglected to fix it, and the shaking worsened until I cleaned the throttle body at a repair shop, which solved the problem. Regular maintenance, such as replacing filters and using additives, helps prevent these issues, saving both money and hassle in the long run.
