Why Is There Noise in a New Car's Engine?

[RubyLee]

New car engine noise occurs because the vehicle is in the break-in period, components fit too tightly, operational issues, or the car was driven without proper break-in. Reasons why new cars need a break-in period: Because the components of a newly manufactured car may appear smooth to the naked eye, but under a microscope, they are still rough, with jagged surfaces and even machining burrs. Reasons for driver operational errors: Driving habits, insufficient driving skills. The driver's psychological resilience is weak, quality factors, physiological reasons. The car's own quality issues, variable weather, and harsh weather conditions affecting driving quality.