Cummins Engine Power Shortage and Exhaust Blue Smoke
The engine emits blue smoke at low temperature or small load, and becomes dark gray smoke after the temperature rises, and the power is insufficient.
Reason
When the engine is running, exhaust pipe discharges blue smoke, because the oil enters the combustion chamber, and when the engine is at low temperature or small load, it fails to burn and is discharged as blue smoke. However, when the engine temperature rises or the load increases, the oil vapor is burned and dark gray smoke appears. The reasons for the above phenomenon are:
a. Air intake is not smooth, causing the oil in the supercharger to be sucked into the cylinder to burn.
b. There is too much oil in the oil sump and the oil exceeds the maximum limit.
c. Oil enters the valve guide.
d. Cylinder is heavily bleeding oil.
e. The supercharger rotor shaft is seriously worn and the oil retaining ring is damaged, causing the supercharger to fail to reach the rated speed and oil leakage.
Diagnosis and treatment
a. Check that the air intake is unblocked and check whether there is oil in the supercharger housing.
b. Take out the oil dipstick after the engine is turned off for 5 minutes, and check whether the oil in the oil pan exceeds the maximum limit; if it exceeds, the excess part should be released.
c. If the above inspection is normal, the injector can be removed, check whether the nozzle hole of the needle valve is unobstructed. If the carbon deposit is serious or oily, the organic oil in the cylinder is intruded.
d. Check the upper end of the valve guide oil seal and the gap between the valve and the valve stem is too large. Further, the cylinder head should be removed to check whether the piston ring is stuck in the ring groove, the end gap is opposite, the fracture is weak, the elastic force is weakened, the conical ring or the twist ring is reversed, and the piston, the piston ring and the cylinder are worn excessively. No pull cylinders and other phenomena, if there are abnormal conditions, timely maintenance.
e. Whether oil leakage caused by improper use and improper maintenance of the turbocharger rotor shaft oil seal, mixed into fresh air into the cylinder, or vaporized by high temperature exhaust gas when exhausted from the turbine end with the exhaust gas. If the oil leakage should be replaced, the turbine carbon should be removed and the bearing clearance of the rotor shaft should be checked to avoid damage to the new oil seal.
The above information is really helpful to maintain your Cummins generator.