What Causes Severe Vibration at Idle Speed?
1 Answers
Severe vibration at idle speed can be attributed to the following reasons: Ignition System Malfunction: If there is a fault in the car's ignition system, it can lead to poor ignition system performance, suboptimal spark plug firing, and other issues, resulting in unstable conditions such as vibration during idle. Poor Fuel Quality: Inferior fuel quality can impair engine performance, thereby causing idle vibration. The solution to this problem is to promptly clean the car's "throttle body," which can generally eliminate common faults. Excessive Carbon Deposits: Excessive carbon buildup inside the engine can cause the gasoline sprayed by the cold-start injector to be largely absorbed by the carbon deposits, leading to an overly lean air-fuel mixture during cold starts and making it difficult to start. In such cases, the engine may only start easily once the carbon deposits have absorbed enough gasoline. After starting, the gasoline adsorbed on the carbon deposits is drawn into the cylinders by the engine's vacuum suction force for combustion, which then enriches the air-fuel mixture. This fluctuation between lean and rich mixtures causes idle vibration after a cold start. Abnormal Fuel Pump Pressure: If the fuel pump's supply pressure is abnormal or if the intake pressure sensor provides incorrect readings or performs poorly, it can also lead to vehicle vibration.
