What are the reasons for the BMW 3 Series being difficult to start when cold?

[VanessaLynn]

The reasons for the BMW 3 Series being difficult to start when cold include: abnormal data from the water temperature sensor, fuel injector leakage, poor cylinder gasket sealing, or excessive carbon buildup in the intake tract, intake valves, and combustion chamber. Excessive carbon deposits and dirt in the intake tract can alter the cross-sectional area of the air passage, leading to an overly rich or lean air-fuel mixture, which causes abnormal combustion resulting in engine shaking after startup or even failure to start. The BMW 3 Series is a new-generation sedan product from BMW Group, with a body weight of 1,465 kilograms and equipped with an inline 4-cylinder gasoline engine. In terms of exterior design, the domestic 3 Series largely follows the design style of the overseas version of the new 3 Series. For the interior, the long-wheelbase version retains the main design of the overseas model.