engine knock

English

Noun

engine knock (uncountable)

  1. a rattling, pinging, or tapping sound caused by improper combustion, where the air-fuel mixture ignites spontaneously in the cylinders before the spark plug fires, or in multiple spots simultaneously
    • 2025 September 11, Kate Marvel, “‘We’ve done it before’: how not to lose hope in the fight against ecological disaster”, in The Guardian[1]:
      Once leaded fuel solved the problem of engine knock, cars quickly displaced horses and motorised transportation took over the world.