What are the methods to troubleshoot engine abnormal noise?

[DakotaRose]

Engine abnormal noises mainly include piston ring noise, piston slap, piston pin knocking, and abnormal noise from the upper cylinder ridge. Detailed information is as follows: 1. Piston ring noise: A sharp sound from the upper part of the cylinder during engine acceleration may be caused by piston ring or cylinder wear, piston ring groove breakage, insufficient piston ring tension, etc. 2. Piston slap: Causes of piston slap include piston or cylinder wear, piston skirt breakage, connecting rod bending, excessive clearance between piston and cylinder wall, poor lubrication, bearing wear, etc. 3. Piston pin knocking: Causes of piston pin knocking include piston pin wear, piston pin retainer wear, piston pin seat hole wear, piston pin bushing wear, poor lubrication, bearing wear, etc. 4. Abnormal noise from the upper cylinder ridge: If new piston rings are installed without removing the upper cylinder ridge from the old cylinder, the new piston rings may contact the ridge and produce abnormal noise; if the piston pin is too loose, the connecting rod is loose, or the bearing is out of round, the piston may rise in the cylinder until the first ring contacts the ridge.