What kind of sound is engine piston pin abnormal noise?

[DiJace]

Engine piston pin abnormal noise is a dull and uncontrolled sound. The noise location is in the upper part of the cylinder, and the sound is similar to the collision of two steel balls. Consequences of engine piston pin abnormal noise: If the piston pin abnormal noise is severe, it will damage the piston pin bushing, increase the wear of the connecting rod bearing and the crankshaft connecting rod journal, and in the most severe cases, it may break the piston pin or the top of the connecting rod may damage the cylinder block. Methods to determine engine piston pin abnormal noise: The method of determination is to conduct a cylinder-by-cylinder fuel cut-off test. After the fuel is cut off, the sound will significantly weaken or disappear, and it will become more obvious when the fuel supply is restored. When the throttle is rapidly jiggled, the abnormal noise will be quite obvious, and the noise cycle will change with the engine speed.