MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
96
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Phenomenon and Cause of Malfunction
Troubleshooting
Exhaust with
black smoke
(1) Overload of the diesel engine
(2) Malfunction of the oil supply
system
(3) Leakage of the exhaust valve
caused by bad sealing
(4)
Insufficient
inlet
airflow,
blockage of the air cleaner or the air
inlet pipe
(5) Severe wear of the cylinder hole
and the piston ring
(6) Malfunction or damage of the
turbocharger
(1) Reduce the diesel engine load to the rated
operating range.
(2) See Chapter 11 for troubleshooting the oil
supply system. (see Page 86 ~ 88)
(3) Check the sealing taper face, abrade the
valve seat if necessary.
(4) Clear and wash off the dirt and foreign
substances in the air cleaner, and replace the
filter core if necessary.
(5) Replace the piston ring.
(6) Overhaul or replace the turbocharger.
Exhaust with
white smoke
(1) There is water in the cylinder or
in the diesel
(2) Insufficient combustion of fuel in
some cylinders when the diesel
engine is started
(3) Malfunction of the oil supply
system
(1) Find out the cause of malfunction and resolve
it.
(2) Increase the rotation speed and load of the
diesel engine properly, and run the engine longer.
(3) See Chapter 11 for troubleshooting the oil
supply system. (see Page 86~88)
Exhaust with
blue smoke
(1) Stuck or overly worn piston ring,
insufficient elasticity; the chamfer of
piston ring is reversely installed,
leading to engine oil flowing into the
combustion chamber
(2) Long-term low load operation;
big clearance between the piston
and the cylinder hole, leading the
engine
oil
slipping
into
the
combustion chamber
(3) Too much oil added in the oil pan
(1) Check the piston ring, replace it if necessary.
(2) Increase the load properly or repair the
corresponding parts.
(3) Examine with a dipstick and drain off the
excessive oil.
8. Heavy Oil Consumption and Low pressure of the Diesel Engine Lubrication
System
In order to avoid seizure and early wear of components, the high speed rotating kinematic pairs of the
diesel engine must be adequately lubricated to reduce the wear and take away the heat. Additionally,
lubricating oil can be used to fill up the small clearance between kinematic pairs (such as the piston and
the cylinder inwall) so as to enhance the sealing effect, stop the high pressure gas from leakage and
make the diesel engine easy to start and maintain its original power. As a result, the pressure and the
flow of lubricating oil are required to be at certain levels (idle speed ≥ 0.1 MPa, 0.35 ——0.55 MPa at
other rotation speeds), and the lubricating oil should also be cleaned.
