What are the causes of piston slap after an engine overhaul?

[OJasmine]

Engine overhaul after the production of piston slap causes are: piston and cylinder with excessive clearance, piston direction installed in reverse or piston deformation, cylinder wall lubrication is poor, lubrication conditions are poor, oil pressure is low or oil viscosity is too low, connecting rod bending or twisting deformation, piston connecting rod group assembly makes the piston in the cylinder tilt exceeds the allowable range, etc. The specific causes of piston slap after an engine overhaul are as follows: 1. Due to improper repair, the piston and cylinder fit clearance is too large, or because the cylinder wear is serious, the clearance is too large, the engine at low temperature when the piston clearance is large, the piston slap noise is serious, the engine temperature rises after the piston expansion, making the piston fit clearance smaller, the piston slap noise is reduced or disappeared. 2. The piston direction is installed in reverse or the piston is deformed, destroying the normal clearance between the piston and the cylinder, resulting in piston slap noise. 3. The cylinder wall lubrication is poor, the lubrication conditions are poor, the oil pressure is low or the oil viscosity is too low, the piston and the cylinder wall can not form a normal oil film, the piston and the cylinder directly collide and produce piston slap. 4. The connecting rod is bent or twisted and deformed, and the assembly of the piston connecting rod group causes the piston to tilt in the cylinder beyond the allowable range. Not only does it make the sealing worse and the lubrication conditions worse, but it also causes abnormal wear of the cylinder, which causes the piston and the cylinder wall to collide and produce noise.