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Old 08-02-2009, 04:57 PM
Mavrick14 Mavrick14 is offline
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Re: The knocking sound in engine is produced by which part?

The typical "knocking" is caused by a rod bearing with excessive clearance. When the bearing is worn down, the connecting rod has freeplay around it's journal, and it knocks.

This could be cause by lack of oil, overheating, a spun bearing (which doesnt get oil), or extreme wear from abuse and lack of maintenance.

A worn or torn harmonic damper also makes a knocking sound as well as piston slap. Piston slap happens when the piston is undersized in it's bore, and it rocks back and forth. The piston skirts slap against the cylinder wall and create a slapping/knocking noise.
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