Knock Diagnosis

Definition for Knock
Engine knock refers to various types of engine noise. Heavy knock is usually very loud and the result of broken or excessively worn internal engine components. Light knock is a noticeable noise, but not as loud. Light knock can be caused by worn internal engine components. Loose or broken external engine components can also cause heavy or light knock.





Engine Knocks Cold and Continues for Two-Three Minutes and/or Knock Increases with Engine Torque





Heavy Knock Hot with Torque Applied





Light Knock Hot





Knocks During Initial Start-Up But Last Only a Few Seconds





Knocks at Idle Hot