Diesel engines should be repaired when the following symptoms occur, except when the bushing holds the axle, sticks the cylinder, tampers the cylinder and so on.

2, lack of power, fuel consumption, exhaust smoke. The main reasons are poor cylinder seal, lower compression pressure, increased gas leakage and incomplete fuel combustion, resulting in a decrease in diesel engine power, increased pressure in crankcase, oil channeling outwards, smoking exhaust, and increased fuel consumption.

3, oil consumption increases and pressure drops. The main reason of oil consumption is the wear of piston ring and ring groove, the increase of clearance and the enhancement of pump oil function of piston ring. The elasticity of oil ring decreases after wear, and the oil scraping effect decreases, resulting in more oil entering combustion chamber and blue smoke in exhaust steam. The reason for the decrease of oil pressure is not only that the oil viscosity is too thin and the oil pump is not working well, but also that the matching clearance of crankshaft main journal and connecting rod journal and bearing bush increases after wear and tear, and the oil flows out of the increased clearance, resulting in the decrease of pressure.

4, the different rotating parts produce abnormal sound. The main reason is that after the wear and tear of the crankshaft connecting rod mechanism, the fit clearance increases, and the mechanical parts under alternating load are subjected to additional impact and make noise. If continue to use, it will cause serious accidents.