Great Wall GW4D28 User manual

Preface
Model Gw4D28 diesel engine is developed based on natural air suction diesel engine model 4JB1 whose
technology was introduced from Isuzu, Japan. This engine features low noise, economical efficiency, fast low-
temperature startup, excellent performance in both low and fast speed, low weight, compact dimension, high reliability
and more powerful.
Model GW4D28 diesel engine is suitable for light truck, Pickup, SUV business car, light passenger car and
other machine powered by diesel engine.
To meet the requirement of the maintenance personnel, technical personnel and management personnel, GW4D28
Diesel Engine Service Manual is complied with technical documents up to minute after arrangement and induction.
The content of this manual is full and detailed. Requirements in the manual are clear and operation is brief.The
manual provides guidance for actual maintenance work as well as prodvides technical procedures as a reference for
the repairer, driver, technical personnel and professional manager.
Continuing enrichment and improvement of the manual may result changes to it, however the contents and
specifications are up to the minute. Defects or errors may occur in the manual, whenerver a question arises regarding
this manual, please consult us.
Final authority for the interpretation of this manual belongs to Great Wall Motor Co., Ltd.

bk

bu
Model GW 4D28 diesel engine
Service Manual
Maintenance documents fk
Mechanical system bj
4D28 engine bk
Fuel system cr
Cooling system `l
Starting system pq
Charging device `e
Exhaust system bu

IN-1
Maintenance documents
Fault diagnosis and troubleshooting ........................... IN-2
Main data and specifications ....................................... IN-11
Maintenance standard................................................. IN-13
Maintenance work ....................................................... IN-15
Fault diagnosis and troubleshooting ........................... IN-23
Special tools ................................................................ IN-31
Page
IN
Maintenance documents-Fault diagnosis and troubleshooting

IN-2
Examination Causes Corrections
1. The starter does not work
Storage battery
Contact failure of the storage battery terminals because of
oxidization corrosion. Clean and refasten the terminals of storage battery.
Uncharged or uncharged sufciently of the storage battery Charge or replace the storage battery.
Loose or rupture of the generator belt Adjust or replace the generator belt
Fuse Short-circuit or damage of the fuse Replace the fuse
Starter switch Failure of the starter switch or the relay Replace the starter switch or the relay
Starter Failure of the electromagnetic switch or the relay Repair or replace the electromagnetic switch.
Starter failure Repair or replace the starter.
2. The starter works but the engine can not rotate
Storage battery
Contact failure of the storage battery terminals because of
oxidization corrosion. Clean and refasten the terminals of storage battery.
Uncharged or uncharged sufciently of the storage battery Charge or replace the storage battery.
Loose or rupture of the fan Adjust or replace the fan belt
Starter
Pinion damage Replace the pinion.
Failure of the electromagnetic switch Repair or replace the electromagnetic switch.
The brush damaged or its spring too soft Replace the brush or brush spring
Engine Seizing or other damage of the piston or crankshaft bearings Repair or replace related parts
3. The engine runs but can not ignited to start
Engine stop
mechanism Damage of fuel shut-off electromagnetic valve Replace the fuel shut-off electromagnetic valve
Fuel did not ow into the injection pump
Fuel Fuel tank empty Fill in the fuel tank to full
Fuel pipe
system Fuel pipes blocked or damaged, or fuel pipe joint loose Repair or replace the fuel pipes or refasten the fuel
joint
Fuel lter
Overow valve of fuel lter can not close Repair or replace the overow valve of fuel lter
Fuel lter elements blockage Replace the fuel lter elements
Fuel system Air in the fuel system Let air in the fuel system out
Fuel delivery
pump Failure of the fuel delivery pump Repair or replace the fuel delivery pump
Fuel ows into the injection pump
Fuel Fuel type incorrect Use qualied fuel
water exists in the fuel system Replacement fuel
Fuel system Air in the fuel system Let air in the fuel system out
Injector
Injector seized Replace the injector
Injection starting pressure too low or bad atomization of the
injector Adjust or replace the injector
Injection pump
Delivery valve damaged causing fuel drops back after injection Replace the delivery valve
Motion failure of injection pump control rack repair or replace the fuel delivery pump control rack
Injection pump plunger damaged or blocked Replace injection pump plunger coupling parts
Seizing or other damage of injection pump driving shaft Replace the driving shaft
Injection pump governor spring blocked Replace the injection pump governor spring
Maintenance documents-Fault diagnosis and troubleshooting
Fault diagnosis and troubleshooting
1.Difcult to start the engine

IN-3
Examination Causes Corrections
4. Fast startup system
Preparations:
1.Disconnect lead socket joint of the temperature switch.
2.Determine if the preheating plug is switching
(a)Ensure the starting switch is “opened”
(b)Connect the cylinder wall and any preheating plug with a voltmeter
(c)Turn the starting switch to “close” position.
If the preheating plug is switching, the voltmeter will display voltage (12V)
If the voltmeter nger does not move, it means that the preheating plug is not switched
3.Failure repair
The preheating plug is switching
The indicating light of the
preheating plug is not on
Indicating light bulb damage Replace the bulb
Fast starting timer Fast starting timer damage Replace the fast starting timer
The indicating light of the
preheating plug is on for 0.3
second
Fast starting timer damage Replace the fast starting timer
The indicating light of the
preheating plug is on for 3.5
second
Turn the starting switch from “start” back to
“close” after the engine has been started, if
the preheating plug relay keeps closing for
less than 14 seconds, then it indicates that the
fast starting up timer is damaged.
Replace the fast starting timer
Turn the starting switch from “open”
to “close” , if the preheating plug relay
keeps closing for less than 14 seconds,
then it indicates that the fast starting up
timer is damaged.
Replace the fast starting timer
temperature switch Temperature switch damage Replace the temperature switch
Preheating plug connection Preheating plug not connected Replace the preheating plug
The preheating plug is not connected
The indicating light of the
preheating plug is not on Indicating light fuse broke Replace the fuse
Fast starting timer Fast starting timer damage Replace the fast starting timer
The indicating light of the
preheating plug is on for 3.5
second
Preheating plug relay damage The
preheating plug is not switching when
the starting switch turns from “open” to “
close”.
Replace the preheating plug
Preheating plug relay wires damage Repair or replace the wires
Damage of fuse or wires The preheating
plug is switching when the starting switch
turns from “open” to “close”.
Replace the fuses or wires
2.Unstable idle speed
Maintenance documents-Fault diagnosis and troubleshooting
Examination Causes Corrections
Idle speed system Idle speed improper adjustment Adjust the idle speed
High idle speed controlling
apparatus
High idle speed controlling apparatus
damage
Repair or replace the high idle speed
controlling apparatus
Throttle valve control
system Throttle valve control system damage Repair or replace the throttle valve control system
Fuel system
Fuel leakage of blockage of the fuel
system Repair or replace the fuel system
Air in the fuel system Let air in the fuel system out
Water in the fuel system Replace fuel
Fuel lter Fuel lter elements blockage Replace the fuel lter elements

IN-4
Examination Causes Corrections
Delivery pump Delivery pump damage Repair or replace the fuel delivery pump
Fuel sprayer
Fuel sprayer seized Replace the fuel sprayer
Injection starting pressure too low or bad
atomization of the oil sprayer Adjust or replace the sprayer
Injection pump
Delivery valve damaged causing fuel oil
drops back after injection Replace the delivery valve
Adjustment of injection timing improper Adjust injection timing
Fuel injection insufcient Adjust injection quantity
Idle spring damaged Replace the idle spring
Governor control rod damaged Repair or replace the governor control rod
Improper adjustment of adjuster valve Adjust or replace the adjuster valve
Plunger spring failure Replace the plunger spring
Plunger wear Replace the plunger coupling parts
Cam wear Replace the cam.
Air valve clearance Improper adjustment of air valve clearance Adjust the air valve clearance
Compressing pressure
Damage of the cylinder cover gasket
Cylinder bush wear
Piston ring adhesion
Replace related parts
3.Power insufcient
Examination Causes Corrections
Air lter Air lter elements blockage Clean or replace the air lter elements
Fuel oil Water in the fuel Replace fuel
Fuel oil lter Fuel lter elements blockage Replace the fuel lter elements
Oil sprayer
Sprayer seized Replace the sprayer
Injection starting pressure too low or bad
atomization of the sprayer
Adjust or replace the sprayer
High pressure oil pipe
Damage or blockage of the high pressure oil
pressure
Replace the high pressure pipe
Delivery pump Delivery pump damage Repair or replace the delivery pump
Injection pump
Incorrect adjustment of injection timing Incorrect adjustment of injection timing
Plunger wear Plunger wear
Speed adjustment spring too soft Speed adjustment spring too soft
Cam wear Cam wear
Incorrect adjustment of injection timing Incorrect adjustment of injection timing
Plunger wear Plunger wear
Speed adjustment spring too soft Speed adjustment spring too soft
Cam wear Cam wear
Air valve clearance Improper adjustment of air valve clearance Adjust the air valve clearance
Compressing pressure
Damage of the cylinder cover gasket
Cylinder bush wear
Piston ring adhesion
Replace related parts
Air valve spring Air valve spring too soft or rupture Replace the air valve spring
exhaustion system Exhaustion system blockage Clean exhausting pipes
Seal of full load adjustment
screws
Screw seals has been damaged or improperly
adjusted
Adjust and reseal the adjustment screws
Maintenance documents-Fault diagnosis and troubleshooting

IN-5
4.Fuel consumption too large
Examine Causes Corrections
Fuel system Fuel leakage Repair or change the according spare part of
fuel system
air lter Air lter elements blockage Clean or replace the air lter elements
Idle speed Improper adjustment of the idle speed Adjust the idle speed
Oil sprayer Injection starting pressure too low of the
injector
Adjust or replace the injector
Valve clearance Improper adjustment of valve clearance Adjust the valve clearance
Compressing
pressure
Damage of the cylinder cover gasket
Cylinder bush wear Piston ring adhesion Replace related parts
valve spring Valve spring too soft or rupture Replace the valve spring
5.Engine oil consumption too large
Examine Causes Correction
Engine Oil Engine oil designation incorrect Replace engine oil
Engine oil overplus Calibrate engine oil liquid surface
Oil seal and gasket Leakage of engine oil from the oil seal and/
or the gasket
Replace the oil seal and/or gasket
Air ventilation port Air ventilation port blockage Clean the air ventilation port
Air intake valve,
exhaust valve
Wear of the air intake valve, exhaust valve
and valve seat cone surfaces
Replace the air intake valve, exhaust valve
and the valve guide pipe, grind the cone
surface of the valve seat.
6.Engine overheat
Examine Causes Correction
Cooling water Shortage of cooling water Supplement of cooling water
Fan clutch Engine oil leakage from the fan clutch Replace the fan clutch
Fan belt Loose or rupture of the fan inducing
slipping Replace the fan belt
Radiator
Radiator cover damage or radiator core
blockage
Replace radiator cover or clean the radiator
core
Water pump water pump damage Repair or replace the water pump
Cylinder cover gasket Cylinder cover gasket damage causes
cooling water leakage
Replace the gasket
Thermostat thermostat damage Replace the thermostat
Cooling system Cooling system blockage with foreign
matters
Cooling system blockage with foreign
matters
Oil injection timing oil injection timing incorrect Adjust oil injection timing
7. White smoke arises from the engine exhaustion fume
Examine Causes Correction
Cooling water Shortage of cooling water Supplement of cooling water
Fuel Water in the fuel Replace fuel
Injection timing Injection timing lag Adjust oil injection timing
Compressing pressure
Damage of the cylinder cover gasket
Cylinder bush wear
Piston ring adhesion
Replace related parts
Oil seal of the air intake
valve, exhaust valve
Valve oil seal damage
Wear or the valve rod or valve guide pipe
Replace the valve oil seal or valve and valve
guide pipe
Maintenance documents-Fault diagnosis and troubleshooting

IN-6
8.Smoke arises from the engine
Examine Causes Correction
Air lter Air lter elements blockage Clean or replace the air lter elements
Injector Injection starting pressure too low or bad atomization
of the injector Adjust or replace the injector
Injection timing Injection timing incorrect Adjust oil injection timing
Injection pump
Delivery valve damaged causing fuel drops back after
injection Replace the delivery valve
Injection overplus Adjust oil injection quantity
9.Engine oil pressure insufcient
Examination Causes Corrections
Engine oil Engine oil designation incorrect
Engine oil insufcient
Replace engine oil
Supplement engine oil
Engine oil pressure gauge
or assembly pressure
gauge indicating light
Damage of engine oil pressure gauge or assembly
pressure gauge indicating light
Repair or replace engine oil pressure gauge or
assembly pressure gauge indicating ligh
Engine oil lter Engine oil lter elements blockage Replace the engine oil lter elements
Safety valve or by-pass
valve Safety valve blocked or by-pass valve spring too soft Replace the safety valve or by-pass valve
Engine oil pump Engine oil pump lter screen blocked Clean the engine oil pump lter screen
Relate parts wear of the engine oil pump Replace related parts of the engine oil pump
Rockshaft Camshaft and its bearings wear Replace the rockshaft bearings
Camshaft Camshaft and its bearings wear Replace the camshaft and its bearings wear
Crankshaft and bearing Crankshaft and its bearings wear Replace the crankshaft and its bearings wear
10. Abnormal noise from the engine
Examination Causes Corrections
1.Engine knock
Examine if the engine has been preheated before failure examination.
Fuel Fuel designation incorrect Replace fuel
Injection timing Improper injection timing Adjust oil injection timing
Injector Injection starting pressure too low or bad atomization
of the injector Adjust or replace the injector
Compressing pressure Damage of the cylinder cover gasket
Piston ring breakage Replace related parts
2.Gas leakage noise
Exhaust pipe Exhaust pipe joint loose
Exhaustion pipe breakage
Tighten the exhaust pipe joints
Replace the exhaust pipe
Injector and/or preheating
plug Injector and/or preheating plug loose
Tighten and fasten the injector and/or
preheating plug
Replace the washer
Exhaust manifold Exhaust manifold loose Tighten the exhaust manifold
Cylinder cover gasket Damage of the cylinder cover gasket Replace the cylinder cover gasket
3.Continuous noise
Fan belt Fan belt slack Readjust tension of the fan belt
Cooling fan Cooling fan loose Fasten the cooling fan
Water pump bearing Wear or damage of the water pump bearings Replace the water pump bearings
AC electric generator or
vacuum pump Damage of AC electric generator or vacuum pump Repair or replace the AC electric generator or vacuum pump
Valve clearance Improper adjustment of valve clearance Adjust the valve clearance
Maintenance documents-Fault diagnosis and troubleshooting

IN-7
Examination Causes Corrections
4.Flapping noise
valve clearance Improper adjustment of valve clearance Adjust the valve clearance
rockshaft Rockshaft bearings wear Replace the rockshaft bearings
Flywheel Flywheel bolts loose Fasten ywheel bolts
crankshaft and/or thrust
bearing Wear of crankshaft and/or thrust bearing Replace the crankshaft and/or thrust bearing
crankshaft and/or connecting
rod bearing Wear of crankshaft and/or connecting rod bearing Replace the crankshaft and/or connecting rod bearing
Connecting rod bushing
and piston pin
Damage or wear of the connecting rod bushing
and piston pin
Replace the connecting rod bushing and piston
pin
Piston and cylinder casing Wear or damage of piston and cylinder casing Replace the piston and cylinder casing
11. Engine cooling failures
Examination Causes Corrections
Engine overheat
Shortage of cooling water Supplement of cooling water
Constant temperature device damage Replace the constant temperature device
Loose or rupture of the fan inducing slipping Replace the fan belt
Radiator damage or radiator core blockage Replace radiator cover or clean the radiator core
water pump damage repair or replace the water pump
Cylinder gasket damage causes cooling water
leakage Replace the cylinder gasket
thermostat damage Replace the thermostat
Cooling system blockage with foreign matters Clean the cooling system
Injection timing incorrect Adjust oil injection timing
Exhaustion system blockage Clean exhausting system
Injection overplus Adjust oil injection quantity
Damage of the cylinder cover gasket Replace the cylinder cover gasket
Too low of the engine oil liquid surface or engine
oil unqualied Supplement or replace engine oil
Engine overcooling thermostat damage Replace the thermostat
Preheating time too
long of the engine
thermostat damage Replace the thermostat
Constant temperature device damage Replace the constant temperature device
Maintenance documents-Fault diagnosis and troubleshooting

IN-8
Examine if the storage battery is normal and then diagnose as follow:
starter do not rotatestarter do not rotate
Examine the storage batteryExamine the storage battery
Storage battery failure or lifeStorage battery failure or life Storage battery is normalStorage battery is normal
replace the storage batteryreplace the storage battery
Examine the wiring terminalExamine the wiring terminal
Terminals connection is normalTerminals connection is normal
Interruption of terminalsInterruption of terminals
Examine the starter or its switchExamine the starter or its switch
Clean the storage battery terminals and
reconnect them
Clean the storage battery terminals and
reconnect them
There is any failureThere is any failure
Repair or replaceRepair or replace
Switch on head light and starter switchSwitch on head light and starter switch
The head light is brightThe head light is bright
The head light is not bright or too darkThe head light is not bright or too dark
(a) open circuit of the starter
(b) Winding open circuit of
the starter
(c) Starter switch failure
(a) open circuit of the starter
(b) Winding open circuit of
the starter
(c) Starter switch failure
(a) Storage battery charged insufcient
(b) Winding short circuit of the starter
(c) Starter parts failure
(a) Storage battery charged insufcient
(b) Winding short circuit of the starter
(c) Starter parts failure
Maintenance documents-Fault diagnosis and troubleshooting

IN-9
Engagement failure of the pinion and gear ringEngagement failure of the pinion and gear ring
When the starting switch turns to “start” position,
examine if there is voltage on the electromagnetic
switch terminals
When the starting switch turns to “start” position,
examine if there is voltage on the electromagnetic
switch terminals
NoNo
YesYes
oror
In this condition, examine if the voltage of re-
starting relay electromagnetic switch plug 3BW
is proper.
In this condition, examine if the voltage of re-
starting relay electromagnetic switch plug 3BW
is proper.
Starter sliding
friction too large
Starter sliding
friction too large
Severe wear of the
pinion and gear ring
Severe wear of the
pinion and gear ring
improperimproper
properproper
repair or replace
the starter.
repair or replace
the starter.
repair or replace the
starter, replace the
gear ring
repair or replace the
starter, replace the
gear ring Break circuit between
the starting switch and
the electromagnetic
switch or connection
failure
Break circuit between
the starting switch and
the electromagnetic
switch or connection
failure
Examine if there
is voltage on the
re-starting relay
starting switch plug.
Examine if there
is voltage on the
re-starting relay
starting switch plug.
repairrepair
nono
yesyes
Break circuit between
the starting switch and
the storage battery or
connection failure
Break circuit between
the starting switch and
the storage battery or
connection failure
Failure of starting
switch connection
Failure of starting
switch connection
Replace the starting
switch
Replace the starting
switch repairrepair
Maintenance documents-Fault diagnosis and troubleshooting

IN-10
OrOr
Although the starting switch turns to “start” position,
but the electromagnetic switch does not work
Although the starting switch turns to “start” position,
but the electromagnetic switch does not work
when the starting switch turns to “start” position,
examine if there is voltage on
when the starting switch turns to “start” position,
examine if there is voltage on
NoNo
YesYes
Examine if the instruments indicating lights are properExamine if the instruments indicating lights are proper
Examine the earthing cablesExamine the earthing cables
AbnormalAbnormal
NormalNormal
Not goodNot good
All rightAll right
Failure of storage
battery and the
starting switch
connection
Failure of storage
battery and the
starting switch
connection
Examine if the
terminals “S” are
closed between the
starting switch and
the electromagnetic
Examine if the
terminals “S” are
closed between the
starting switch and
the electromagnetic
RepairRepair
open circuit or burning
out of the electromagnetic
switch or wiring
open circuit or burning
out of the electromagnetic
switch or wiring
sliding parts
of the pinion
can not move
sliding parts
of the pinion
can not move
RepairRepair
Examine the
starter relay
Examine the
starter relay
Starter switch connection
failure
Starter switch connection
failure
Repair or replace the starterRepair or replace the starter
Replace the starting switchReplace the starting switch
Examine the
clutch and the
starting switch
Examine the
clutch and the
starting switch
The pinion and the gear ring engages but the engine can not runThe pinion and the gear ring engages but the engine can not run
Examine the earthing cableExamine the earthing cable
GoodGood BadBad
Repair or replace the earthing cableRepair or replace the earthing cable
Pinion clutch
slipping
Pinion clutch
slipping
Open circuit or
damage of the
armature coil
Open circuit or
damage of the
armature coil
Op e n c irc uit
or damage of
the excitation
wirings
Op e n c irc uit
or damage of
the excitation
wirings
Burnout of
electromagnetic
switch
Burnout of
electromagnetic
switch
Electric brush or
rectier failure
Electric brush or
rectier failure
Repair or replace the starterRepair or replace the starter
Maintenance documents-Fault diagnosis and troubleshooting

IN-11
Main data and specications
Engine model
Items 4D28
Engine style Four strokes, valve-in-head, straight,
water cooling
Combustion chamber style ω style
Cylinder bush style Dry, chroming stainless steel tube
Cylinder number=cylinder diameter×stroke mm 4—93×102
Piston ring number Air ring: 2 Oil ring: 1
Total displacement ml 2771
Compression ratio (for type I) 18.2
Compressing pressure kPa 3038
Engine weight (net) kg About 229
Fuel injection sequence 1—3—4—2
Fuel injection timing degree Front of top dead centre 14
Prescribed fuel brand 0# light diesel (-20#light diesel for cold
area)
Idle speed
r/min 750—790
Valve space (cold condition) Air intake valve
mm 0.40
Exhaust valve mm 0.40
Valve space (hot condition) Inlet valve
mm 0.45
Exhaust valve mm 0.45
Inlet valve Open (front of top dead centre)
degree 24.5
close (rear of top dead centre) degree 55.5
Exhaust valve
Open (front of bottom
dead centre) degree 54
close (rear of top dead centre) degree 26
Lubricating system
Lubrication method Compound of pressure lubrication and
splashing lubrication
Prescribed engine oil brand CD class diesel engine oil
Engine oil pump type Gear type
Engine oil lter type Full-flow, replaceable paper core
cartridge
Engine oil capacity (including the engine oil lter) L 6.6—7.1
Engine oil cooler type Water cooling
Fuel system
Fuel pump type Bosch distributing pump
Governor type Mechanical (portion speed change)
Injector type Hole type
Open pressure of injector kPa 18142
Fuel lter type Paper filter cartridge and water
seperator
Air lter type Dry paper lter cartridge
AC electric generator specications V-A 12—50
Starter specications V-KW 12—2.8
Main data and specications
Maintenance documents-Main data and specications

IN-12
Cooling method Closed forced circulation
Radiator type Tube-band
Heat transfer kcal/h 71400
Heat transfer area m2 11.78
Front face area m2 0.216
Net weight kg 10.71
Valve opening pressure kPa 88—118
Capacity of coolant L 3.1
Coolant pump type Centrifugal wheel
Transmission ratio of the belt 1.2
Thermostat type Wax pellet (with swing valve)
Valve opening temperature ℃ 82
Valve wide opening temperature ℃ 95
Total capacity of coolant L 10
Startup system
Model
Items
DENSOR
Rating
Voltage V
Output power KW
Startup time sec
Pinion teeth number
12
2.8
5
9
Rotation direction (from the pinion end) Clockwise
Weight (about) kg 5.4
No load characteristic
Voltage/current V/A
Rotation speed r/min
11.5/120 or less
4000 or more
Load characteristic
Voltage/current V/A
Torque N·m
Rotation speed r/min
7.5/500 or less
13.0
1400 or more
Brake characteristic
Voltage/current V/A
Torque N·m
2.0/850 or less
15.7 or more
Charging appliance
Model
Items
HITACHILR150—449B
Rated voltage V 14
Rated current A 50
Rotation direction (from the driving end) Clockwise
Effective diameter of the pulley mm 80
Weight ( including pump) kg 6.0
Cooling system
Maintenance documents-Main data and specications

IN-13
Engine mechanical system Unit: mm
Parts Items Standard value Operating limit Notes
Cylinder cover
Flatness of the cylinder cover and outlet manifolds
mating surfaces.
Cylinder cover height
Angularity of cylinder cover bottom surface
Angularity of manifold mating surface
Combustion chamber clank block falling
Pressure exerted on the combustion chamber clank block
≤0.05
92±0.05
≤0.05
≤0.05
——
44100-53900N
0.2
——
0.20
0.20
0.02
——
Can not be
reground
Cylinder spring
Free height
Verticality
Spring tension(N)
Installation height
48.0
1.5
296
38.9
47.10
1.7
257.9
——
Valve and valve
guide pipe
Valve rod diameter
Air Inlet
Exhaust
Clearance between valve and valve guide pipe
Air Inlet
Exhaust
Valve guide pipe top height (measured from the cylinder
cover top plane)
Margin of the valve guide pipe
valve thickness
Air Inlet
Exhaust
Valve seat contact angle (degree)
Valve seat contact width
Air Inlet
Exhaust
7.95
7.93
0.039—0.069
0.064—0.096
13.0
1.1
1.79
1.83
45
1.7
2.0
7.880
7.850
0.200
0.250
——
1.6
1.5
1.5
＜45
2.2
2.5
Push rod Degree of curvature 0.40 ≤ 0.4
Camshaft
Axial gap
cam height
Journal diameter
Radial jumping
Camshaft bearing inner diameter
Camshaft oil gap
0.08
42.02
49.96±0.015
≤0.02
500
+0.03
0.025—0.085
0.2
41.65
49.60
0.10
50.08
0.12
Transverse
member
Outer diameter
Oil gap (between the rocker and the rockshaft)
12.97—12.99
0.03
12.95
0.10
Radial direction
jump of the
rockshaft
The outer diameter of the rockshaft
The inner diameter of the rockshaft
Oil gap(between the crank arm the crankshaft)
Radial direction jump of the rockshaft
18.98—19.00
19.036—19.060
0.06—0.08
0.20
18.90
19.10
0.10
≤0.2
Engine oil pump
Oil gap
Between the pump and the gear wheel
Between the pump cover and the gear wheel
0.13—0.14
0.02—0.07
0.15
0.15
Maintenance standard
Maintenance documents-Maintenance standard

IN-14
Unit: mm
Parts Items Standard value Operating limit Notes
Crankshaft
Axial gap
Radial jumping of the main journal and the
connecting rod journal
Main journal diameter
Connecting rod journal diameter
Non-uniform wear of the main journal and
the connecting rod journal
Gap between the connecting rod journal and
the connecting rod bearing
Gap between the main journal and the main
bearing
0.10
≤0.05
70
53
≤0.05
0.029—0.066
0.035—0.080
0.30
0.08
69.91
52.90
0.08
0.100
0.110
Piston, piston
pin, piston
ring and the
connecting
rod
Piston ring diameter
Piston gap (between the piston and the
cylinder bush)
Opening clearance of the piston ring
The rst ring
The second ring
Oil ring
93
0.025—0.045
0.20—0.40
0.20—0.40
0.10—0.30
>93.024
<0.025
1.5
1.5
1.5
Clearance of the piston ring
The rst ring
The second ring
Oil ring
Piston pin diameter
Assembly Interference (between piston pin
and its seat hole)
(Cold state)
Connecting rod adjustment
Rod body linearity
Parallelization of two reducer holes
Gap between the piston pin and the
connecting rod bushing
Axial gap of the connecting rod
Oil gap
between the connecting rod journal and the
connecting rod reducer
0.090—0.125
0.050—0.075
——
31
0.002—0.015
≤0.08
≤0.05
0.008—0.020
0.230
0.029—0.066
——
0.15
0.15
30.970
0.04
0.20
0.15
0.050
0.35
0.10
Engine body
Engine body top surface distortion
Cylinder hole diameter
Cylinder bush projection quantity
Inner diameter of the cylinder casing
Inner diameter of the cylinder casing (rough
hole)
——
95
0.0-0.1
93.020—93.060
95.011—95.050
0.20
——
——
——
——
Maintenance standard (Supplement)
Maintenance documents-Maintenance standard

IN-15
Maintenance work
Attention:
Normal maintenance works shall be carried by qualified
maintenance personnel.
Mark
Engine serial number
The serial number of the engine is stamped on the left side of
front end of the engine body.
Air filter
Cleaning methods vary for different filter cores.
Filter core blockage by dust
Turn filter core by hand, at the same time blow air into the filter
core, then the dust can be blown off.
The pressure of compressed air is 392 to 490kPa.
Attention
Do not hit the filter core onto other objects for the purpose
of cleaning; otherwise the filter core will be damaged.
Filter core blockage with carbon and dust
(a) Prepare original air filter core cleaning solution produced
by the Great Wall Car Company, and dilute it with water.
(b) Immerse the filter core into the cleaning solution for
about 20 minutes.
(c) Take out filter core from clearner,make it well cleaned,
water pressure should not exceed 274kpa
(d) Dry filter core in a well-ventilating site
Accelerate drying speed with electric fan.
Attention:
Do not accelerate drying process with compressed air or
naked flame,or, the filter core will be damaged.
Normally, a filter core can be dried for two to three days, and
then spare parts are needed at hand for temporary usage.
Pick the filter core out of cleaning solution and wash it with
flowing water.
The water pressure shall not more than 274kPa.
Lubricating system
Main oil filter ( paper type filter core)
replacement procedure
Maintenance documents-Maintenance work

IN-16
Lubricating system
Main oil filter ( paper type filter core)
replacement procedure
(a) Loose oil drain plug and drain oil.
(b) Tighten again the oil drain plug after several minutes.
(c) wist off used filter counter clockwise with filter wrench.
(d) Clean the mating surface of oil cooler.It can make new oil
filter assembly suitable.
(e) Apply a thin film of oil on the O-ring surface.
(f) Screw down the new oil filter until the O-ring and sealing
surface bind together.
(g) Screw down for 1.25 turns with filter wrench.
Filter wrench: 5-8840-0200-0
5-8840-0202-0
5-8840-0209-0
(h) Examine the oil level, add to the prescribed level if required.
0.7LOil filling capacity is 0.7L.
(i)
Start the engine and check if there is any leakage in the oil filter.
Fuel system
Replacement procedure of fuel filter
(a) Twist off used filter counter clockwise with filter wrench.
Filter wrench: 5-8840-0253-0(J-22700)
(b) Clean the mating surface of the filter base plate.
It can make new fuel filter assembly suitable.
(c) Screw down new fuel filter until it can contact with the
sealing surface.
(d) Screw down for 2/3 turns with filter wrench.
Filter wrench: 5-8840-0253-0(J-22700)
Maintenance documents-Maintenance work