What is the difference between engine noise and engine sound?

[StKaleb]

Here are the differences between engine noise and engine sound: The definitions of the two are different: Noise refers to the large amount of unpleasant sounds emitted by various components and assemblies during the operation of a car, while abnormal sound refers to the noises that exceed the limits specified in technical documents during the operation of a car. The situations in which they occur are different: As a mechanical product, an engine will inevitably produce noise during operation. Noise is a normal phenomenon, and certain measures can be taken to reduce its intensity, but it cannot be completely eliminated. Abnormal sounds, however, are non-normal phenomena and are manifestations or precursors of car faults. The causes of the two are different: For example, intake and exhaust noise, combustion noise, friction noise, gear noise, hydraulic flow noise (engine oil, coolant, etc.), and air noise (mainly from the fan) can all lead to noise. Abnormal engine sounds are mainly caused by increased component gaps, abnormal wear, component damage, poor lubrication, etc. Common abnormal engine sounds include piston knocking, piston pin noise, crankshaft main bearing noise, connecting rod bearing noise, valve tappet noise, valve lifter and guide noise, ignition knocking, timing gear or timing chain noise, belt noise, etc.