Why do Diesel engines have that distinctive sound to them when compared to gasoline engines?

Question

Why do Diesel engines have that distinctive sound to them when compared to gasoline engines?

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Answer 1

when you compress air it heats up, in a diesel engine this heat is used to ignite the air fuel mixture. in a gasoline engine its ignited with an electrical spark. with the gasoline engine the combustion propagates smoothly from a single point, the spark plug. where as with diesel there can be multiple ignition points that can collide and causing vibrations and a distinct sound.