Sound

Possible Cause

Clicking sound that usually quiets down as you raise the engine RPM or  a double knock sound

Valve and hydraulic lifter or a lack of oil and excessive clearance between the piston pin and the piston

Whine

If heard when turning, check the power steering fluid as lower levels may cause this.

Pinging or rattling when accelerating the vehicle 

Air/fuel mixture in the engine cylinder being ignited prematurely by the heat of compression as the piston is moving up on the compression stroke 

Growling

Growling is usually due to a faulty bearing in the tensioner pulley, an accessory component, or an idler pulley - if used

Screech or high pitch whining 

A bearing (fan belt idler pulley, alternator pulley, etc.) can make screeching or whining noises

Chirping 

Chirping is a result of belt vibration. This can occur due to improperly aligned pulleys, damp or wet conditions, and/or belt glazing. Minor pulley misalignment can result from excessive manufacturing tolerances or installation errors. 

Knock that is heard towards the bottom of the engine

Connecting rod noise is caused by excessive clearance between the crankshaft and the connecting rod bearing surface

Rumbling or thumping sound deep in the engine when accelerating 

Crankshaft bearing noise due to worn surfaces or possibly from low oil pressure 

Muffled bell sound or a hollow clatter deep in the engine and is more noticeable when the engine is cold 

Piston slap caused by excessive clearance between the piston skirt and the cylinder wall 

Squealing (often heard at engine startup, sudden acceleration, air conditioning turn-on, or during a U-turn)

Typically caused by belt slippage due to improper tension and/or a badly glazed belt. Serpentine belt systems typically employ a spring loaded belt tensioning pulley. Sometimes these can just go soft.

Gravel in engine

Cavitation in the water pump