Chapter III Malfunction Diagnosis and Troubleshooting
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
95
6. Abnormal Noise from Diesel Engine
Check whether the diesel engine is adequately preheated before malfunction diagnosis.
Phenomenon
Cause of Malfunctions
Troubleshooting
Sound of knocking
the diesel engine
cylinder
(1) Inappropriate fuel
(2) Malfunction of the fuel injector or
bad connection of the circuit
(3) Damage of the cylinder gasket,
breakage of the piston ring
(4) Wrong output signal of the coolant
temperature sensor, knocking the
cylinder when the heater accelerates
(1) Choose the specified fuel according
to the ambient temperature.
(2) Replace the fuel injector and fasten
the cable connection.
(3) Check the cylinder compression
pressure and replace relative parts.
(4) Replace the coolant temperature
sensor.
Noise from gas
leakage
(1) Loose connection and breakage of
the exhaust pipe
(2) Looseness of the fuel injector
and/or the glow plug
(3) Looseness of the exhaust manifold
pipe
(4) Damage of the cylinder gasket
(1) Fasten
the
exhaust
pipe
connection, replace the exhaust pipe.
(2) Fasten the fuel injector and/or the
glow plug, replace the gasket.
(3) Fasten the exhaust manifold pipe
.
(4) Replace the cylinder gasket.
Continual noise
(1) Wear or damage of the water pump
bearing
(2) Damage of the generator
(1) Replace the water pump bearing.
(2) Replace or repair the generator.
Slapping noise
(1) Looseness of the flywheel bolts
(2) Damage or wear of the crankshaft
and/or the thrust plate
(3) Wear of the crankshaft and the
connecting rod bearing shell
(4) Wear or damage of the connecting
rod bushing and the piston pin
(5) Wear or damage of the piston
(1) Fasten the flywheel bolts.
.
(2) Replace the crankshaft and/or the
thrust plate.
(3) Replace the crankshaft and/or the
connecting rod bearing shell.
(4) Replace
the
connecting
rod
bushing and the piston pin.
(5) Replace the piston.
7. Abnormal Smoke from Diesel Engine
If the technical status of the diesel engine is fine, the exhaust emitted from the exhaust pipe should be
colorless, or light blue and light grey when the engine is under normal load. The exhaust at the moment
consists of carbon dioxide, vapor, a little carbon monoxide and non-completely burned lubricating oil
(which makes the exhaust light blue or light grey).
When the exhaust pipe of the diesel engine emits
black, blue or white smoke, it means that the technical status of the diesel engine is abnormal.
