What causes the BMW 5 Series to shake during a cold start?

[LydiaRose]

BMW 5 Series cold start shaking specific reasons are introduced as follows: 1. Excessive carbon buildup in the throttle body, fuel injectors, or intake manifold—it could be one of these or all of them. 2. 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, which causes shaking. 3. Mechanical failures in components such as ignition coils, spark plugs, or fuel injectors, leading to cylinder misfires; low oil pressure or cylinder pressure, resulting in insufficient power, etc. 4. Oxidized or low-grade engine oil, mainly due to poor low-temperature fluidity, leading to inadequate engine protection during cold starts.