What Causes Abnormal Noise in the Engine Camshaft?

[PaulRose]

The causes of abnormal noise in the engine camshaft: 1. Excessive clearance between the camshaft and its bushings; 2. Rotation of the camshaft bushings; 3. Bending or deformation of the camshaft; 4. Excessive axial clearance of the camshaft; 5. Burning or detachment of the camshaft bushing alloy. The phenomenon of camshaft abnormal noise is the sound emitted between the camshaft bearings and the shaft during engine operation, which is a rhythmic, dull metallic knocking sound. The noise is more noticeable when idling or slightly above idle speed, especially when listening near each camshaft bearing. Methods to identify camshaft abnormal noise: 1. If the noise originates from the camshaft side, gradually changing the throttle will make the noise clearer at idle, more pronounced at medium speed, and become chaotic or weaken until disappearing at high speed, which usually indicates camshaft abnormal noise; 2. Remove the valve cover and press the camshaft with a metal rod to see if the noise changes. If the noise changes, it is the camshaft noise.