What causes abnormal noise when the car just starts moving?

[Corey]

Abnormal noise when starting the car is caused by carbon deposits in the throttle or the gasoline filter not being replaced for a long time, resulting in an excessively lean air-fuel mixture that causes engine idle vibration. Related introduction about cold-start abnormal noise is as follows: Introduction to engine idle vibration: During cold starts, the water temperature is low, and the engine oil hasn't fully circulated for lubrication. The engine noise will be louder, with higher idle speed and vibration. As the engine runs, the water temperature gradually rises, the oil lubricates, the noise will decrease, the idle speed will reach normal RPM, and the vibration will disappear. Inspection introduction: It is recommended to first use a computer to check if there are any fault codes in the engine system, and clean the throttle, intake tract, fuel injectors, and catalytic converter. Replace the gasoline filter if necessary.