What Causes Engine Idle Vibration When Water Temperature Rises?

[Myra]

Idle vibration is most likely caused by carbon deposits in the engine or throttle body. Here are the relevant explanations: 1. Causes of idle vibration: When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector will be largely absorbed by the carbon deposits, resulting in an excessively lean air-fuel mixture during cold starts and making it difficult to start. In this situation, the engine can only start easily after the carbon deposits have absorbed enough gasoline to reach saturation. After starting, the gasoline adsorbed on the carbon deposits will be drawn into the combustion chamber by the engine's vacuum suction force and burned, making the air-fuel mixture too rich. The constantly changing lean and rich air-fuel mixture causes idle vibration after a cold start. 2. Inspection method: When the engine idle is unstable, the first step is to adjust the idle speed. If the problem persists after idle adjustment, then check whether the idle jet and idle air jet are clogged.