Chapter III Malfunction Diagnosis and Troubleshooting
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
93
Malfunction in cylinder
head components:
insufficient power,
poor performance, air
leakage, black smoke
and abnormal
knocking sounds.
(1) Air leakage in the
junction surface of the
cylinder head and the
cylinder body; loose
cylinder head bolt or
damaged cylinder body
gasket.
(2) Loose air intake and
exhaust valves
(3) Air leakage in the fuel
injector hole or damaged
copper gasket
(1) Screw up the cylinder head bolt according to
the specified torque or replace the cylinder head
gasket.
(2) Remove and check the air intake and exhaust
valves, repair or grind the valve or the matching
surface of the valve.
(3) Remove the fuel injector for repair, clear up and
replace the damaged parts.
Malfunction in the
crank connecting rod
mechanism
Seizure between the
connecting rod small end
bushing and the piston
pin
Remove the oil pan, check whether the connecting
rod big end is axially wobbling, if not, remove the
piston connecting rod components for examination
and repair.
High pressure oil
pump, fuel injector
Malfunctioning high
pressure oil pump and
fuel injector
Examine and repair or replace the high pressure oil
pump and the fuel injector
Malfunction in the
pressure sensor of
high pressure oil track
Damaged pressure
sensor of high pressure
oil track
Replace the pressure sensor of high pressure oil
track
Turbocharger
Air leakage or failure in
the air outlet pipe of
turbocharger
Tighten up the connecting air outlet pipe of
turbocharger or replace the connecting piece
4. Excessive Fuel Consumption of Diesel Engine
Part, Phenomenon and Cause of Malfunction
Troubleshooting
Fuel system
Fuel leakage
Examine and repair, and replace the relevant parts
in the fuel system if necessary
Air cleaner
Blockage in the air cleaner
elements
Clean or replace the air cleaner elements
Fuel injector
and control
circuits
Poor fuel injection or poor
controlling for fuel injection
Check the fuel injector and fuel injection control
system
Compression
pressure
Damaged cylinder gasket, sticky
piston ring
Examine and repair, and replace the cylinder
gasket and piston ring and relevant parts
Valve spring
Too loose or fractured valve spring
Examine and repair, and replace the valve spring
5. Abnormal Noise During the Diesel Engine Running
First, identify the abnormal noise, whether the knocking noise is due to abnormal erupting or due to
abnormal running of parts within the engine body. Then check and diagnose the noise source according
