Chapter 1 Engine Overview ......................................................................................................01
Section 1 Basic Structure and Working Principle of Engine. ......................................................................01
Section 2 Structural Characteristic of Engine .............................................................................................04
Section 3 Engine Technical Performance and Parameters ......................................................................12
Section 4 Engine Servicing Datasheet .......................................................................................................18
Section 5 Maintenance of Engine ...............................................................................................................23
Chapter 2 Cylinder Block Assembly ....................................................................................26
Section 1 Structural Characteristic of Cylinder Block ................................................................................26
Section 2 Detach, Assembly and Servicing of Cylinder Block ..................................................................27
Chapter 3 Cylinder Head Assembly ...................................................................................45
Section 1 Structural Characteristic of Cylinder Head ................................................................................45
Section 2 Detach, Assembly and Repair of Cylinder Head ......................................................................45
Chapter 4 Piston & Connecting Rod Mechanism ....................................................69
Section 1 Construction of Piston & Connecting Rod Mechanism ............................................................69
Section 2 Dismantling and Inspection of the Connecting-rod and its Bearing ......................................72
Section 3 Common Faults and Troubleshooting of the Piston Connecting-rod Mechanism ................73
Chapter 5 Crank Mechanism ..................................................................................................76
Section 1 Structural Characteristics of Crank Mechanism ........................................................................76
Section 2 Disassembly & Maintenance of Crank Mechanism ..................................................................78
Section 3 Common Faults and Troubleshooting of Crank Mechanism ...................................................83
Chapter 6 Valve Train ....................................................................................................................84
CONTENTS
Section 1 Make-up of Valve Train & its Design Features ............................................................................84
Section 2 Valve Timing ..................................................................................................................................85
Section 3 Make-up of Valve train Assembly and its Features ...................................................................86
Section 4 Service of Valve Train ...................................................................................................................89
Section 5 Common Faults and Troubleshooting of Valve train ................................................................93
Chapter 7 Fuel Supply System .................................................................................................94
Section 1 Makeup and Features of Fuel Supply System for Electronic Fuel Injection Engine ................94
Section 2 Matters Needing Attention in Use and Maintenance of Electronic Fuel Injection System....99
Section 3 Troubleshooting the Electronic Fuel Injection System .............................................................102
Section 4 Evaporative Emission & Positive Crankcase Ventilation Control System ..............................124
Chapter 8 Ignition System .........................................................................................................127
Section 1 Introduction to Ignition System ..................................................................................................127
Section 2 Troubleshooting of Ignition System ...........................................................................................128
Chapter 9 Lubrication System ...............................................................................................132
Section 1 Makeup and Features of Lubrication System ..........................................................................132
Section 2 Examination & Maintenance of Lubrication System ..............................................................136
Section 3 Common Faults and Troubleshooting of Lubrication System ................................................141
Chapter 10 Cooling System .....................................................................................................143
Section 1 Composition & Features of Cooling System ............................................................................143
Section 2 Inspection and Maintenance of Cooling System ...................................................................147
Section 3 Common Faults and Troubleshooting of Cooling System ......................................................149
Chapter 11 Clutch ..........................................................................................................................150
Section 1 Structure of Clutch and Its Operating Mechanism .................................................................150
Section 2 Clutch Troubleshooting ..............................................................................................................152
Section 3 Assembly and Adjustment of Clutch and its Operating Mechanism ...................................155
Section 4 Common Faults and Troubleshooting of Clutch .....................................................................158
Chapter 12 Common Faults and Troubleshooting of Engine ........................160
Section 1 Overview .....................................................................................................................................160
Section 2 Determination and Elimination of Common Faults in Engine ................................................160
Section 3 Determination and Elimination of Abnormal Noises in the Engine ........................................171
Chapter 13 Power source .........................................................................................................173
Section 1 Structure of Clutch and Its Operating Mechanism .................................................................173
Section 2 Battery ..........................................................................................................................................175
Section 3 Normal Malfunction of Charging System and Troubleshooting ............................................176
Chapter 14 Starter ..........................................................................................................................177
Section 1 Structure of Starter ......................................................................................................................177
Section 2 Working Principle of Starter ........................................................................................................178
Section 3 Attentions in Use of Starter .........................................................................................................178
Section 4 Troubleshooting of Starter ..........................................................................................................179
Chapter 15 Engine Management System ....................................................................180
Section 1 System Profile ..............................................................................................................................180
Section 2 System Composition and Working Principle ............................................................................181
Chapter 16 Engine Electronic Control System ..........................................................184
Section 1 General Structure of Engine Electronic Control System .........................................................184
Section 2 Structural Principle of the Components of the Engine Electronic Control System ..............184
Engine provides power to the automobile. Presently, internal combustion engine is widely applied in the automobile. It’s
a kind of thermal machine that can control the fuel combustion in the cylinder to generate heat energy effectively, and then
convert the heat energy into mechanical energy that drives the piston in the cylinder to make reciprocating movement as
the way to output the power by the connecting rod, the crankshaft and the flywheel. The automobile runs with the power
transferred by the internal combustion engine to the automobile driving mechanism. Most of the internal combustion
engines providing power to the automobile are gasoline or diesel engines based on the fuel for combustion. The power to
GEELY car comes from the gasoline engine equipped with the electronic fuel injection system. It’s made of the machine
unit, crank connecting rod mechanism, valve train, fuel supply system, ignition system, cooling system, lubricating system,
startup system and management system.
1. Machine Unit
The machine unit is mainly composed of cylinder head, cylinder block and oil pan. It’s the basis of assembling the
engine mechanisms and systems, and the base to support the engine in normal operation. In another word, many parts of
the machine unit have multiple specific functions. For example, the internal walls of cylinder block and cylinder head make
up the combustion room, but they are also the components of crankshaft connecting rod mechanism, fuel supply system,
cooling system and lubricating system. The machine unit is designed to bear ultra heat or mechanical load.
2. Crankshaft Connecting Rod Mechanism
The crankshaft connecting rod mechanism is composed of body, piston, connecting rod, crankshaft, flywheel and crank
shield. It converts the heat generated by engine combustion into mechanical energy, namely, converts the piston linear
reciprocating movement into the crankshaft and flywheel rotations, and then the flywheel outputs the power. The flywheel
is designed to keep the engine in stable rotation by the rotating inertia.
3. Intake Mechanism
The intake mechanism is composed of cylinder head, intake valve, exhaust valve, cam shaft, tappet, valve spring, cam
shaft timing gear, and timing belt. The intake mechanism is designed to open the intake valve in time, take in the combus-
tible gas mixture into the cylinder, and emit the post-combustion exhaust gas out of the cylinder in time.
4. Fuel Supply System
The fuel supply system is composed of gasoline pump, gasoline filter, gasoline distribution pipe, pressure regulator,
fuel injector, fuel tank, air filter, throttle body, intake manifold, exhaust manifold, exhaust gas purifier, and exhaust muffler.
The fuel supply system is designed to mix gasoline and air into high-quality combustible gas mixture, send it to the cylinder
for combustion, and emit the exhaust gas out of the engine.
5. Ignition System
The ignition system is composed of storage battery, engine, ignition coil, high-voltage wire and spark plug. The ignition
system is designed to make sure the compressed gas mixture to be ignited right at the preset moment. The ignition system is one
of the characteristics of gasoline engine to differentiate from the diesel engine.
Chapter 1 Engine Overview
I. Basic Structure of Engine
Section 1 Basic Structure and Working Principle of Engine
1
2
6. Cooling System
The cooling system is composed of pump, radiator, fan, water inlet and outlet pipes, thermostat, the drain valve of
cylinder, and the gas water cavity. The cooling system is designed to emit the thermal energy in the heated components
to the air, so that the engine can work under thermo-equilibrium with powerful, cost-effective, reliable and durable features.
7. Lubricating System
The lubricating system is composed of oil pan, oil collector and filter, oil pump, pressure limit pump, as well as oil
passage, oil filter, and oil gauge in the machine unit. The lubricating system is designed to transmit the lubricant onto the
working surfaces of components in relative motion, so as to have the surfaces lubricated, cooled, sealed, antirust-treated
and cleaned, and in this way guarantee a normal and reliable operation for the engine.
8. Startup System
The startup system is composed of startup motor and its accessories. It’s designed to start up the engine from statistic
mode to automatic operation.
9. Engine Management System
The engine management system is also called the engine control system. It’s composed of sensors that measure the
engine operation status and parameters, the Electronic Control Unit (ECU) and the controlled acting components.
The system is based on the Electronic Fuel Injection (EFI), with ECU controlling the Electronic Spark Advance (ESA)
and the Idle Speed Control (ISC) so that the engine works in optimal condition.
II. Operational Principle of Engine
Fig. 1 Working Principle of Engine
The engine works continuously to convert the heat generated by combustion into the mechanical energy. It never stops
repeating the 4 strokes in the cylinder, including intake stroke, compression stroke, power stroke and exhaust stroke.
Below is a description of an operational cycle of 4-stroke gasoline engine, taking a single-cylinder engine shown in Fig.
1 as an example.
Piston Stroke
TDC
BDC
3
An operational cycle of 4-stroke engine is made of the intake, compression, power and exhaust strokes. When the
piston moves from Top Dead Center (TDC) to the Bottom Dead Center (BDC), the crank turns 180°. The distance from
TDC to BDC is called piston stroke.
1. Intake Stroke
The intake stroke is the process of taking in the combustible gas mixture into the cylinder. The intake valve opens right
before the piston approaches the TDC, and the exhaust valve closes immediately after the piston goes down. The intake
and exhaust valves form a proper overlap angle when they’re open simultaneously, which helps emitting the exhaust gas
effectively and improving the scavenge quality with the gas inertia. As the piston goes down further, the gas capacity
expands to produce ultra vacuum in the cylinder, so more gas mixture is taken in. When the piston reaches the BDC, the
intake valve is still open. Till the piston goes up and more combustible gas mixture goes into the cylinder with inertia, the
intake valve will close after the crank turns to the proper delay angle.
If the operational capacity of cylinder is fixed, in order to enable the engine to produce more power, the gas mixture
shall be taken in as much as possible in the intake stroke. In this sense, multiple valves, turbine mid-air cooler and
electronic fuel injector are applied to produce more high-quality combustion gas mixture
2. Compression Stroke
The compression stroke is the process of compressing the combustible gas mixture in the cylinder. The piston goes up
from the BDC, with the intake and exhaust valves closed. The pressure and temperature of combustible gas mixture in the
cylinder increase rapidly, so the heat-atomized fuel and gas become more even that helps improving the combustion
quality and the power capability. As improving the compression pressure may result in certain danger, the compression
ratio shall be keep at the best level. Improving properly the engine compression ratio, i.e. the ratio of maximal cylinder
capacity vs post-compression minimal capacity, may make the engine more powerful and cost-effective.
3. Power Stroke
The power stroke is the process in that the combustible gas mixture burns and expands to generate power in the
cylinder. At this moment, the intake valve is still closed. Before the piston goes up the TDC, the temperature and pressure
of gas mixture increase a lot, which drives the ECU to select and figure out the best ignition timing, and then the spark plug
will generate spark to ignite the combustible gas mixture. The gas mixture burns and releases heat that makes the
temperature and pressure increase sharply in the cylinder, and the maximal pressure occurs at the crank angle of 10° to
20° after reaching TDC. When the piston goes down after reaching the TDC, the expansion-to-power process begins. The
piston drives the crank and flywheel rotating with the connecting rod, and outputs the driving torque. When the piston
reaches the BDC, the power stroke ends. In order to keep the engine more powerful, cost-effective and less-polluting, we
have made great efforts to improve the combustion, make full use of the fuel, and purify the exhaust gas, and we’ll go on
with the efforts
4. Exhaust Stroke
The exhaust stroke is the process of emitting exhaust gas out of the cylinder. Before the piston goes down to the BDC
in the power stroke, the exhaust valve opens, and the hot combustion gas turns to be exhaust gas after the expansion-to-
power process, and then begins to go out of the cylinder. The piston goes up after it reaches the BDC, and the exhaust gas
is extruded. Before the piston reaches the TDC, the intake valve begins to open for scavenge. Of course, when the piston
reaches the TDC, the exhaust valve will close after a period of delay.
The piston goes down from the TDC into a new operational cycle. With the operational cycles made up of the above-
mentioned 4 strokes, the engine works repeatedly and outputs non-stop power that drives the car forward
4
TStructural Characteristic of Engine Engine and Engine are new products based on the features
of domestic. overseas same type engine and the modern up-to-date engine technologies It applies the technologies of
electronic control fuel multipoint sequence injection, group ignition, and close-ring control system provided by the United
Automobile Electronic of Shanghai (UAES). The multipoint sequence injection guarantees that the combustible gas
mixtures are produced in different cylinders under identical conditions, so as to improve the mixture quality; the ECU
updates and selects the best injection timing, producing highly precise control of fuel quality. It’s structured without power
distributor and with 2 ignition coil that can generate voltage as high as 10 to 35kV for ignition.
With the overall displacement of and . engine and engine are cylinder-in-line,
water-cooling. 4-stroke gasoline engines equipped with double over head camshaft, 16 valve, and electronic control fuel
injection. There’re the oxygen sensor and the three-way catalytic converter in the exhaust pipe. ECU controls the switch of
cooling fan in the engine according to the change of cooling water temperature in order to keep the cooling water in normal
temperature. Fig. 2 and Fig. 3 are the assembly drawing and the components assembly drawing of engine. Fig.
4 and Fig. 5 are the assembly drawings of engine with power system and auxiliaries respectively.
Fig. 6 is the layout of electronic control fuel injection system in engine.
Fig. 2 Assembly Drawing of MR479Q/MR479QA Engine
Section 2 Structural Characteristic of Engine
MR481QA
IL481Q
1.342L
1.498L
1.587L
1.762L
MR479Q
MR479QA
MR481QA
JL481Q
MR479Q
MR479QA
MR479Q
MR479QA
MR479Q
MR479QA
5
Fig. 3 Components Assembly Drawing of MR479Q/MR479QA Engine
6
Fig. 4 MR479Q/MR479QA Engine and Its Power System
7
Fig. 5 Assembly Drawing of Engine and Its Auxiliaries
MR479Q
MR479QA
8
Fig. 6 Electronic Control Fuel Injection System in Engine
MR479Q
MR479QA
9
Fig. 7 Front view of Engine
JL481Q
MR481QA
10
Fig. 8 Sectional elevation of Engine
JL481Q
MR481QA
11
Fig. 9 Electronic Control Fuel Injection System in Engine
JL481Q
MR481QA
12
4-cylinder in line, water-cooling,
dual-roof convex shaft, 16 valves, belt
and gear driven, hip-shaped combustion chamber
78.7×69 78.7×77
1.342 1.498
9.3 9.8
800±50
Dynamic adjusted by ECD with the condition
0.20±0.05
0.30±0.05
63/6000 69/6000
110/5200 128/3400
≤259 ≤279
≤0.1
≤50
CO≤2.3g/Km,HC≤0.2g/Km,NOx≤0.15g/Km,with OBD
function
NO.93 or above Lead-free vehicle gasoline
Pressure and splash combined
SAE 10W-30 or SAE 10W- 40 SAE15W-40
SAE 5W-30 in frigid area, API quality rate: SG or above
≥90
294 ~539
3.5 (full in dry mode),3.1 (full in wetmode)
Force-cycle, water-cooling
0.8 ± 0.1
Type
Bore × stroke (mm × mm)
Displacement (L)
Compression ratio
Rotation at idle speed (r/min)
Ignition timing
Valve clearance Intake(mm)
(In cold state) Exhaust (mm)
maximum power (KW/r/min)
Maximal torque (N.m/r/min)
Minimal fuel consumption ratio at full load (g/kw.h)
Emission at idle speed CO (%)
HC (PPm)
Test cycle emission (GB
III
)
Number of fuel
Lubrication
Oil specification
Oil pressure Idle (kpa)
3,000r/min (kpa)
Oil capacity (L)
Cooling
Spark clearance (mm)
MR479Q MR479QA
Section 3 Engine Technical Performance and Parameters
1.Major Technical Parameters of MR479Q Engine and MR479QA Engine
13
Type
Bore × stroke (mm × mm)
Displacement (L)
Compression ratio
Rotation at idle speed (r/min)
Ignition timing
Valve clearance Intake(mm)
(In cold state) Exhaust (mm)
maximum power (KW/r/min)
Maximal torque (N.m/r/min)
Minimal fuel consumption ratio at full load (g/kw.h)
Emission at idle speed CO (%)
HC (PPm)
Number of fuel
Lubrication
Oil specification
Oil pressure Idle (kpa)
3,000r/min (kpa)
Oil capacity (L)
Cooling
Spark clearance (mm)
MR481QA JL481Q
II. Major Technical Parameters of MR481QA Engine and JL481Q Engine
4-cylinder in line, water-cooling, dual-roof convex shaft,
16 valves, belt and gear driven, hip-shaped combustion
81×77 81×85.5
1.587 1.762
9.6 9.6
800±50
Dynamic adjusted by ECD with the condition
0.20±0.05
0.30±0.05
78.7/6000 83.1/5600
137/4400 156.8/3400
≤269 ≤269
≤0.1
≤50
NO.93 or above Lead-free vehicle gasoline
Pressure and splash combined
SAE 10W-30 or SAE 10W-40. SAE15W-40.
SAE 5W-30 in frigid area. API quality rate: SG or above
≥90
294 to 539
3.5 (full in dry mode).3.1 (full in wet mode)
Force-cycle. water-cooling
1.0 ± 0.050
14
III. Engine performance curve
Engine feature refers to the rule in that the engine performance indicators change with the operational conditions. The
speed feature of engine is commonly used to define the rule in that the power, torque and fuel consumption ratio change
with the rotating speed in the case of fixed engine load (the throttle opening angle is fixed). The speed feature in the case
of full engine load (the throttle is completely opened) is called the exterior feature. The exterior feature curve describes the
maximal power, maximal torque, minimal specific fuel consumption of engine and the corresponding changes of engine
rotation speed, as shown in Fig. 10, Fig. 11, Fig. 12 and Fig. 13.
Fig. 10 Exterior Feature of MR479Q Engine
ge( g/kwh)
Rotation Speed
n r/min
Power
Me (N.m)
Torque
Pe(Kw)
Fuel Consumption Ratio
15
ge(g/kwh)
n
r/min
Power
Me (N.m)
Torque
Pe(Kw)
Fuel Consumption
Ratio
Rotation Speed
Fig. 11
Exterior Feature of MR479QA Engine
16
n r/min
ge(g/kwh)
Fuel Consumption
Ratio
Rotation Speed
Power
Me (N.m)
Torque
Pe(Kw)
Exterior Feature of MR481QA Engine
Fig. 12
17
Fig. 13 Exterior Feature of JL481Q Engine
Power
Me (N.m)
Torque
Pe(Kw)
ge(g/kwh)
Fuel Consumption
Ratio
18
Section 4 Engine Servicing Specifications
I.MR479Q/MR479QA/JL481Q/MR481QA Engine Servicing Technical Datasheet (Table 1 to Table 4)
Table 1 Mechanical Part of MR479Q/MR479QA/JL481Q/MR481QA Engine Servicing Datasheet
Servicing Data
0.030
0.050
0.080
0.080
0.100
1.000-1.400
1.000-1.400
45°
0.500
5- 23
1.000-1.400
45.5°±15’
5.960- 5.975
5.950
5.960-?5.975
5.950
0.800-1.200
0.500
0.800-1.200
0.500
0.025-0.058
0.080
0.025-0.058
0.080
39±0.30
38.570
31.700
160±8N
150
0.015-0.055
0.075
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Maximal correction
Standard
Allowed limit
Intake
Exhaust
Standard
Standard
Seat surface width
(mm)
Valve race surface angle
Intake bearing hole
Exhaust bearing hole
Standard
Lower surface flatness
(mm)
Flatness of manifold
interface (mm)
Valve seat
Allowed concave in valve seat surface (mm)
Standard value of cam
shaft bearing hole (mm)
Standard interface width
with valve seat (mm)
Taper angle
Outer diameter of
valve stem (mm)
Thickness of
valve seat edge
Clearance between valve
stem and valve
conduit (mm)
Valve spring
Valve tappet
Intake
Exhaust
Intake
Exhaust
Intake
Exhaust
Free height (mm)
Installation height(mm)
Installation load (N)
Allowed limit of perpendicularity(mm)
Oil film clearance
Cylinder head
Valve Valve
Valve
conduit
1- 25
+0.021
0
4- 23
+0.021
0
1.2
A
Name of item
φ
φ
φ
φ
φ
φ
φ
φ
φ
19
Exhaust cam shaft
0.040-0.091
0.110
Exhaust 42.01±0.04
Exhaust 41.850
Exhaust 42.01±0.04
Exhaust 41.850
0.030
0.035-0.072
0.120
0.035-0.072
0.120
0.040-0.091
0.120
0.020-0.200
0.300
8.75±0.03
8.6
0.040
0.050
78.730
81.03
0.0065
0.0065
0.040
0.040
0.075 – 0.095
0.115
79.115 - 79.145
79.315 - 79.345
81.445 – 81.485
81.645 – 81.685
I) 78.665- 78.655,II) 78.665 78.675
III) 78.675-78.685
I) 80.955- 80.965,II) 80.965- 80.975
III) 80.975-80.985
Intake cam shaft
0.032-0.085
0.110
Intake 41.76±0.04
Intake 41.650
Intake 42.665±0.04
Intake 42.554
0.030
0.040-0.082
0.120
0.040-0.082
0.120
0.032-0.085
0.120
MR479Q and
MR479QA
JL481Q and
MR481QA
Cam height (mm)
(Base circle + lift)
Clearance between
journal and
bearing(mm)
Cylinder bore (mm)
Piston skirt
dimension for
servicing (mm)
Skirt H=18,H=16
Diameter standard
Axle clearance (mm)
Name of item
Servicing data
Journal uneven abrasion (mm)
Thrust bearing clearance (mm)
Gear clearance (mm)
Upper surface flatness (mm)
Diameter of cylinder head bolt (mm)
Cylinder hole roundness (mm)
Cylinder hole perpendicularity (mm)
Cylinder hole dimension for
servicing (mm)
Clearance between piston skirt and
cylinder hole (mm)
MR479Q and
MR479QA
JL481Q and
MR481QA
MR479Q and
MR479QA
JL481Q and
MR481QA
1 to 2 for front
3 to 5 for middle
and rear
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Plus 0.5
Plus 0.7
Standard
Allowed limit
Plus 0.5
Plus 0.7
Plus 0.5
Plus 0.7
MR479Q and
MR479QA
JL481Q and
MR481QA
Camshaft Cylinder block Piston
78.700
+0.030
0
79.200
+0.030
0
79.400
+0.030
0
81.0
+0.030
0
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
φ
20
Outer diameter (mm)
?20
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
Allowed limit
Standard
0.002-0.013
0.017-0.044
0.2-0.4
1.050 for 1 ring,1.200 for 2 ring
0.2-0.7
1.100
0.20-0.055
0.04
0.060-0.160
0.180
0.03
0.06
0.020-0.051
0.070
0.150-0.30
0.35
0.005
0.01
0.020
0.015-0.033
0.100
0.040-0.220
0.250
47.982 – 48.000
47.745 – 47.755
39.985 – 40.000
39.745 – 39.755
47.982 – 48
47.745 – 47.755
2.450-2.480
2.350
0.015
0.100
1.486 – 1.490
1.490 – 1.494
1.494 – 1.498
1.606 – 1.610
1.610 – 1.614
1.614 – 1.618
Central wall thickness of
connecting rod bearing shell (mm)
Clutch interface run-out (mm)
Thickness of thrust plate (mm)
Connecting rod journal
diameter(mm)
Master journal diameter (mm)
Axle clearance (mm)
Journal uneven abrasion (mm)
cylindricity
Clearance to ring
groove edge(mm)
Opening clearance (mm)
1 to 2 rings
Oil ring
1 to 2 rings
MR479Q
MR479QA
MR481QA
Oil ring
Interference with connecting rod (mm)
Clearance to piston (mm)
Allowed bend (per 100mm) (mm)
Allowed twist (per 100mm) (mm)
Axial clearance of connection
rod big end (mm)
Clearance between connecting rod bearing and
connecting rod journal(mm)
Clearance between master
journal and bearing (mm
Plus for servicing
JL481Q
Piston ringPiston Pin
Connecting rod Crankshaft Bearing shell
Flywheel
+0.016
+0.010
φ
φ
φ
φ
φ
φ φ
φ
φ
φ
φ
φ
21
Standard
Central wall thickness of
connecting rod bearing shell (mm)
Table 3 Fastening Torque Specifications of Major Bolts and Nuts in
Table 2 Main Adjusting Parameters for MR479Q/MR479QA/JL481Q/MR481QA Engine
Plus for servicing
2.002 – 2.005
2.005 – 2.008
2.008 – 2.011
2.011 – 2.014
2.014 – 2.017
2.122 – 2.125
2.125 – 2.128
2.128 – 2.131
2.131 – 2.134
2.134 – 2.137
Torque N.m
18
13
10.8
20
59
37
127
29
Rotation of 90°
Rotation of 90°
31
20
9.3
19
15
Quantity
4
22
4
2
1
1
1
10
3
2
1
7
2
Specification
M14 x 1.25 S=16
M6 x 40 S=10
M6 nut S=10
M8 x 31 S=12
M10 x 1.25 x 23 S=14
M10 x 1.25 x 40 S=10
M12 x 1.25 x 31 S=17
M10 x 1.25 x 90
Dodecagonal bolt S=10.3, e=11.5
M10 x 1.25 x 20 S=14
M8 x 12 S=12
M6 x 12 S=8
M8 x 30 S=12
M8 x 50 S=12
Part
Cylinder head
Cylinder head
Cylinder head
Cylinder head
Camshaft
Cylinder block
Crankshaft
Cylinder block
Cylinder block
Cylinder block
Cylinder head
Cylinder head
No.2 water inlet
Cylinder head
Intake manifold
Name
Spark plug
Cam bearing cover (bolt)
Cylinder head hood (bolt)
Ignition device
Camshaft timing belt wheel
Belt tension wheel
Crankshaft tension wheel
Cylinder head (1st screwing)
Cylinder head (2nd screwing
Cylinder head (3rd screwing)
Generator stand
No.2 water inlet
Oil position ruler conduit
Intake manifold
Transmit pipe
Adjusting parameter
Under pressure of 98N, deflection of 7 to 9mm for new
belt, and 11.5 to 13.5mm for used belt
Intake 0.20±0.05
Exhaust 0.30±0.05
0.8±0.1;1±0.05(MR481QA,JL481Q
800±50
At idle speed (rotation = 800±50r/min), 8±2° before
TDC (T terminal connected)
CO≤0.2%, HC≤60PPm (QB)
3.5L (full in dry), 3.1L (full in wet)
Oil level between F line and L line of ruler
Deflection is 5 to 6mm under pressure of 20N
Item
Tension of belts in generator and pump
Valve clearance (mm) (in cold state)
Spark plug clearance (mm)
Rotation at idle speed (r/min)
Ignition timing
Pollutant emission at idle speed
Oil capacity
Tension of timing belt
Bearing shell
22
Torque N.m
29
10.2
21
44
31
22
22
22
34
59
59
17
60
70
80
70
9.3
20
20
51
39
5.6
78/85
4.9
44
30
7±1
Quantity
2
2
1
1
1
2
1
2
5
1
1
4
10
10
10
8
6
1
3
3
2
2
6
19
1
1
2
2
Specification
M12 x 1.25 x 26 S=17
Flange hexagonal nut M6 S=8
M8 x 29 S=12
M8 x 16 S=12
M8
M8 x 54 S=12
M8 x 35 S=12
M8 x 16
M10 x 1.25 Nut S=14
M10 x 1.25 Nut S=14
M10 x 1.25 x 20 S=13
M6 x 12 S=10
M10 x 1.25 x 60 S=14
M10 x 1.25 x 60 S=14
M10 x 1.25 x 60 S=14
M9 x 1 S=14 e=16.2
M6 x 16 S=8
M8
M8 x 35 S=12
M10 x 1.25 x 35 S=13
M10 x 1.25 x 21 S=14
M6 x 13 S=8
M10 x 1.25 x 23 S=17
M6 x 12 S=8
M16 x 1.5
Substandard thread
M10 x 1.25 x 20
M6 x 40
Part
Transmit pipe
Intake manifold
Intake manifold
Cylinder block
Cylinder head
Intake manifold
Cylinder head
Cylinder head
Cylinder head
Exhaust manifold
Cylinder block
Exhaust manifold
Cylinder block
Cylinder block
Cylinder block
Connection rod body
Cylinder block
Cylinder block
Cylinder block
Cylinder block
Cylinder block
Cylinder block
Crankshaft
Cylinder block
Exhaust manifold
Cylinder block
Cylinder head
Regulator seat
Name
Fuel-in pipe
Cooling water bypass hose
Intake manifold seat
Intake manifold seat
Engine stand(RH)
Throttle section
Water inlet stand
Water outlet
Exhaust manifold
Exhaust manifold stand
Exhaust manifold stand
Heat-isolation cover of exhaust pipe
Rear oil seal ring
Knock sensor
Water Pump
Installation rack for RH engine
AC generator adjusting level
Rear end plate
Flywheel
Oil drip pan
Oxygen sensor
Oil filter
Front and rear hooks of
engine Idle regulator
MR479Q
MR479QA
MR481QA
1st screwing by hand.
2st wrenching 3/4 circles
MR479Q
MR479QA
JL481Q
Main bearing
cover
Connecting rod
cover
Connection
rod body
M9 x 1 S=14 e=16.2 8
65
JL481Q
MR481Q
23
In order to extend the engine life, the maintenance shall comply with the following procedures during its running.
1. Daily maintenance
a Check the gasoline, cooling water and oil levels, and add in if necessary.
b Remove the dust or spilled electrolyte on the storage batteries, so as to make sure that the ventilation hole is unblocked.
When the electrolyte is insufficient, add in the distilled water in time.
a Check the leakage of oil or water.
b Judge whether the engine runs properly after its startup through listening, and check the instrument operations.
2. Maintenance per 1,000km of driving
a Complete the daily maintenance.
b Check and adjust what are necessary.
c Check the electrolyte proportion or voltage of storage batteries.
d Check whether the connectors of ECU, generator, spark plug and other electrical accessories are loose.
A Check whether all parts of the gasoline engine are well fastened.
3. Maintenance per 5000km-drive
a Complete the maintenance per 1,000km of driving.
b Check whether the storage batteries develop crack or have electricity leakage.
c Check whether the generator works properly.
d Replace the oil.
4. Seasonal maintenance
a Add anti-freezer into coolant in the winter days.
b Adjust the concentration of storage battery electrolyte on seasonal basis.
1. Maintenance Periods and Maintenance Content
Section 5 Maintenance of Engine
Specification of applicable oil: SAE10W-30 or SAE10W-40, SAE15W-40: frigid zone: SAE5W-30. API grade: above SG.
1. Check whether the engine oil is in bad quality, mixed with water, fading or diluted.
Replace the oil in case the quality apparently deteriorates.
2. Check the oil level
The oil level shall be between L and F in the oil ruler 5 minutes after the engine stops working. If it’s too low, check the
leakage and add in oil to the mark F, but never above F.
3. Replace with new oil
Discharge the oil completely after it works for a period, and replace with the new oil. During the course of replacement,
discharge the used oil from the oil pan when the engine is still hot. If there’s a large quantity of impurities in the oil pan,
wash them out with light spindle oil, but never wash with gasoline or coal oil.
Clean the oil-filling port before injecting oil in it, so as to prevent the impurities from entering together. After adding in the
oil, wait for 5 minutes before checking the height of oil level. After the injection is completed, put on the cap.
II. Maintenance of Lubricating System
When the engine is running, there must be enough cooling water in the cooling system to make sure that the engine
works properly. Therefore, before each drive, the driver shall check and add in timely clean soft water, but is not allowed
to use the unprocessed hard water with high content of alkali or mineral substances.
There shall be no excess rust or furring on the radiator cover or around the water-filling hole of radiator. Mix the high-quality
glycol-based coolant according to the manufacture’s instruction (the recommended concentration is above 50%, but no
higher than 70%), and never use the ethanol-based coolant.
1. Check and Replacement of Timing belt
Check whether the belt is installed properly. If any belt gear tooth is broken or damaged, check whether the camshaft is
stuck; if there’s observable crack or damage on the belt surface, check the positions of belt pilot wheel and each belt wheel;
if the belt gear tooth wears apparently, check whether the timing belt cover is damaged, or installed improperly, or if any
alien substance exists on the belt gear tooth, and replace the belt if necessary. In normal case replace the belt after each
120,000km of driving.
Note: Don’t bend, twist or turn outwards the timing belt, and keep the timing belt off oil, water or vapor.
2. Check and Measurement of Valve Clearance
Note: Check and adjust the valve clearance when the engine is in cold state.
a Turn the crankshaft pulley to align the “V” groove on it to the timing mark “O” on the No.1 timing belt cover. Check
whether the mark “K” on the camshaft timing pulley is in line with the timing mark “U” on the bearing cover. If not, turn the
crankshaft a circle (360°).
b Measure the clearance between the 1, 2 cylinder intake cam and the 1, 3cylinder exhaust cam and the valve tappet with
the thickness meter, and make sure it comply with: 0.15 to 0.25mm for intake, and 0.25 to 0.35mm for exhaust.
c Turn the crankshaft pulley for a circle to align the “V” groove on it with the timing mark “O” on the No.1 timing belt cover.
Check and measure the clearance of 3. 4 cylinder intake valve and 2, 4 cylinder exhaust valve. In normal case, check and
adjust the valve clearance per 40, 000km (or 24 months).
3. Check of Pump Driving (V-type) Belt
III. Maintenance of Cooling System
IV. Check of Engine
Fig. 14 Tightness of water pump driving belt
Water pump
AC
98N
Crankshaft
Check the belt per 10,000km-drive (or 6 months), as follows:
(1) Check visually whether the driving belt groove over-wears, the
sennit looses, or the spoke is striped. Replace the belt if damage is
found.
(2) Impose the belt with the pressure of 98N (10Kgf), and make
sure the belt deflection ∆ is:
∆ = 7 to 9mm for new belt; and ∆ = 11.5 to 13.5mm for old belt.
If the deflection is not in compliance with the above standard,
adjust the belt tension (Fig.14). New belt refers to the belt that has
worked in the running engine for less than 5 minutes; Old belt
refers to the belt that has worked in the running engine for no less
than 5 minutes.
24
4. Replacement of Engine Oil
In normal case replace the engine oil per 5,000km of driving (or 3 months), and replace it per 2,500km of driving in
adverse conditions.
5. Replacement of Oil Filter
Remove the oil filter with the specialized servicing tools, and replace it per 10,000km of driving (or 6 months) in normal
case, and per 5,000km of driving (or 3 months) in adverse condition. Pay attention to the follows during the course of
replacement:
1. Check and clean the installation surface of oil filter.
(1) Check whether the component number of new oil filter is the same as that of the original one.
(2) Paste the clean engine oil upon the gasket of new oil filter.
(3) Screw in the oil filter gently, and screw it down when the gasket touches the base.
(4) Screw 3/4 rounds more with specialized servicing tools.
6. Check and replacement of spark plug
Check it per 10,000km of driving (or 6 months) in normal case, and replace it per 20,000km of driving (or 12 months).
(1) Check visually whether there’s electrode ablation or screw damage in the spark plug. Replace the spark plug if it’s
not in normal condition. The recommended spark plug is: MR479Q/MR479QA DENSO K16R-U, MR481QA/JL481Q
K7RF-11.
(2) Bend the outer side of electrode gently in order to obtain the necessary electrode clearance(0.8mm in normal case).
(3) Install the spark plug using a spark plug wrench with a torque of 18N.m.
7. Replacement of oil filter
Replace it per 40,000km (or 24 months) in normal case.
8. Check and replacement of compulsory ventilation valve PCV in crankshaft box
The PCV valve is installed to reduce the leakage of HC or other poisonous gases.
How to check the PCV valve:
(1) Blow air into the PCV valve from the cylinder cover side, and check whether it’s unblocked.
(2) Blow air into the PCV valve from the intake room side, and check whether it’s blocked.
If the PCV valve fails the above check, it shall be disqualified and replaced.
Note: Don’t take in air through the PCV valve because the petroleum substances inside are poisonous.
Check and replace it per 20,000km of driving (or 12 months) in normal case.
9. Check and replacement of all hoses and connections in engine
Check it per 40,000km of driving (or 24 months) in normal case, and replace it per 80,000km of driving (or 48 months).
After replacement, check it per 20,000km of driving (or 12 months).
25
When the engine is working, the cylinder block withstands high heat and mechanical load. In order to make the engine
work in normal and reliable operation, the cylinder block shall be of high strength, enough rigidity, compact structure, low
weight and easy servicing.
1. Gantry structure, plus well-deployed isolating plate and reinforced rib, provide high anti-bending and anti-twisting
strength.
2. It’s made of alloy casting iron, providing high strength and enough rigidity.
3. Cylinder block is short in length and light in weight. These engines are suitable to the transverse mounting, front installed
and front wheel driving.
4. The cylinder block is compact. The cylinder center distance is 87.5mm. There’s the main oil passage in the cylinder
block, connecting to the oil pump, oil filter, and oil pressure sensor directly. There’s optimized layout for cooling system of
water cavity and water flow. And the servicing is easy (Fig. 15).
Chapter 2 Cylinder Block Assembly
Section 1 Structural Characteristic of Cylinder Block
1
10
10
8
8
9
2
3
4
4
5
7
7
6
6
Fig. 15 Cylinder Block
1.Oil filter compo. 2.Six.flange bolt – grade B 3.RH installation bracket 4.Positioning bush
5.Oil passage screw plug 6.Dowel pin 7.Dowel pin 8. Dowel pin 9.Hang pin 10.Stud-end bolt
26
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