If the unit runs under low load, the following faults will occur with the extension of running time:

1. The piston-cylinder liner is not well sealed, the oil goes up and burns into the combustion chamber, and blue smoke is emitted from the exhaust.

2. For turbocharged diesel engine, the turbocharging pressure is low because of low load and no load. It is easy to lead to the decline of the sealing effect of the supercharger oil seal (non-contact type), and the oil will enter the booster chamber and enter the cylinder with the intake air.

3. Part of the oil that goes up to the cylinder participates in the combustion, part of the oil can not burn completely, carbon deposits are formed at the valve, inlet, piston top, piston ring, etc., and some are discharged with the exhaust. In this way, oil will gradually accumulate in the exhaust port of the cylinder liner, and carbon will also be formed.

4. When the oil in the supercharger chamber accumulates to a certain extent, it will leak out from the bonding surface of the turbocharger.

5. Long-term low-load operation will lead to more serious wear of moving parts, engine combustion environment deterioration and other consequences leading to early overhaul.

Therefore, both naturally aspirated and supercharged diesel engine manufacturers abroad emphasize that the low-load / no-load running time should be reduced as much as possible, and that the minimum load should not be less than 25% of the rated power of the unit.