Why does the car make abnormal noise as soon as it starts?

[ChloeAnn]

The reasons for abnormal noise when the car starts are as follows: 1. Abnormal timing belt: When the engine is running at high temperatures, incorrect matching and installation of the timing belt tensioner will affect the service life of the timing belt. During the car's startup process, whether it's a cold start or a normal temperature start, if there is a squeaking sound, the timing belt should be replaced promptly. 2. The working sound of the fuel pump: After power is turned on, the fuel pump will start working to prepare for starting the engine. If the fuel pump does not work after power is turned on, the fuel supply system will not have sufficient injection pressure when starting the engine, which will make the engine difficult to start. After the car is powered on, the starter gear will also engage with the engine flywheel ring gear. The starter gear is controlled by an electromagnetic coil, which produces a buzzing sound when working. These sounds are normal.