What are the reasons why a Passat won't start?

[McMalia]

Generally, the reason a car won't start is that the vehicle's battery is dead and cannot generate sufficient voltage. Other reasons are as follows: 1. Carburetor issue: usually due to prolonged use. 2. Spark plug issue: sometimes oil may flood the spark plug; check if the spark plug head has oil or is wet, which can also prevent the car from starting. 3. Weather issue: for example, in cold winter weather, it's common to experience difficulty starting the car. 4. Battery issue: if the car won't start, it can easily lead to battery drain, damaging the battery. 5. Idle speed issue: sometimes the car won't start because the idle speed is too low. Normally, in summer, check the tachometer—the pointer should point to one mark or slightly more. In winter, adjust it to one and a half marks or below two.