What Causes a Car Engine to Fail to Start?

[JasonLee]

The reasons why a car engine fails to start include the following: 1. Low temperature, which usually occurs in winter. In such conditions, the viscosity and rotation speed of the car's engine oil decrease, and the battery's ignition energy is reduced, making it difficult to form flammable gases and thus hard to start the engine. 2. Damaged or non-functional spark plugs. Spark plugs are a critical component of the car's ignition system, and the ignition system is key to whether the car's heart (engine) works or not. Therefore, whether the spark plugs can function properly directly affects the vehicle's performance and efficiency. 3. Dead battery. This could be due to reasons like leaving the headlights on for too long, resulting in a drained battery, or the battery's lifespan has expired. It is generally recommended to replace the battery every 2 years. 4. Incorrect gear position. For automatic transmission cars, the gear must be in P (Park) or N (Neutral) when starting. If it's in R (Reverse) or D (Drive), the engine won't start. Some manual transmission cars may also fail to start if the clutch is not depressed.