The Main Reasons For Piston Knocking Are As Follows

(1) The gap between the piston and the cylinder wall is too large.
(2) After running the engine for a period of time, the cylinder piston wears out, coupled with poor lubrication, the clearance between the piston and the cylinder increases due to wear, and a serious step appears slightly below the first air ring, causing the piston to make a strange noise when hitting the cylinder.
(3) After running for a period of time, the piston skirt and cylinder wear severely, causing severe out of roundness and knocking of the cylinder.
(4) Individual connecting rods may deform due to various reasons, causing piston wear, increased clearance, and knocking of the cylinder. Knocking the cylinder with a piston can lead to excessive fuel consumption, engine oil leakage, high oil consumption, and poor fuel efficiency. When the piston strikes the cylinder severely, it can also break the piston, damage the cylinder, and cause the connecting rod to break, damaging the cylinder block.