What Causes Engine Shaking in the New Passat?

[AlejandroAnn]

The causes of engine shaking in the new Passat are as follows: 1. Intake manifold or various valve leaks: Leaks can lead to abnormal engine air intake, causing the air-fuel mixture to be too rich or too lean, resulting in abnormal combustion. This can cause the engine to shake at idle. 2. Excessive carbon buildup in the throttle and intake passages: Too much carbon buildup and dirt in the throttle and surrounding intake passages can change the cross-sectional area of the air passage, preventing the control unit from precisely controlling idle air intake. This leads to an overly rich or lean air-fuel mixture and abnormal combustion. 3. Inaccurate air intake: The control unit receives incorrect signals from the air flow sensor and issues wrong commands, causing inaccurate idle air intake and abnormal air-fuel mixture concentration, which results in abnormal combustion. This is an indirect cause of unstable idle.