1Part I EngineChapter 1 Engine Assembly
(MR479Q, MR479QA, MR481QA)Section 1 Routine Inspection1. Check coolant
2. Check engine oil
3. Check battery
4. Check air cleaner element assembly
5. Check spark plug
6. Check drive belt
Figure 1
Notice:
zCheck the belt deflection at the specified point See (Figure 1).
zSet tension to specified value when installing new belt.
zCheck the deflection to ensure it is below the specified value after the belt runs for over 5 minutes.
zReinstall the belt which has been running for over 5 minutes. The deflection of the old belt is regarded as
the standard for inspection.
zCheck V-belt for tension and distortion after the engine cranks for 2
turns.
7. Check ignition timing See (Figure 2)
a) Warm up the engine.
b) When using fault diagnosis tester
Connect fault diagnosis tester to fault diagnosis interface socket.
Ignition timing:
MR479Q: 10 ± 2° BTDC (before top dead center) at idle
MR479QA: 10 ± 2° BTDC at idle
MR481QA: 10 ± 2° BTDC at idleFigure 2New Belt mm Old Belt mm
Fan Belt 7~
13. 5
Power steering Belt 5~
66~
8
A/C Belt 6. 5
~78~
9 Belt deflection See (Table 1)
Be lt pre ssure : 98NBelt Looseness
Measuring PointWater pump
Power steering
crankshaftgenerator
Air condition
compressor pump11.5~
9
13Section 2 Engine Components Replacement1. Avoid gasoline ejection when work.
2. Drain the coolant to empty.
3. Remove air filter assembly with hose. See (Figure 23)
4. Remove battery
5. Remove fuel delivery pipe sub-assembly
6. Disconnect water hoses, disconnect heater outlet hose
from A/C hose.
7. Loose nut, remove accelerator control cable
8. Remove throttle body assembly
9. Remove power steering pump reservoir assembly
10. Remove front exhaust pipe assembly
11. Remove steering gear boot
12. Seperate steering column assembly. See (Figure 24)
13. Remove front wheel hub nut
14. Disconnect front wheel vehicle speed sensor (with ABS)
15. Detach steering tie rod ball stud pin assembly
16. Detach front lower swing arm sub-assembly
17. Detach front propeller assembly. See (Figure 25)
Detach front propeller from the shaft hub with plastic hammer.
18. Disconnect transmission shift cable or gear shift level assembly
19. Disconnect clutch cylinder assembly or disconnect clutch cable
20. Detach engine assembly and transaxle
(a) Hoisting engine ;
(b) Remove 3 bolts. Detach the right engine mounting bracket. See (Figure 26) ;
(c) Remove 1 bolt. Detach the left engine mounting bracket;
(d) Remove 1 bolt. Detach the rear engine mounting bracket;
(e) Remove engine and transaxle and put them on the pallet;
(f) Jack up the boday.Figure 23
Figure 24
Figure 25 Figure 26
16(c) Install and uniformly tighten connecting bolt in the sequence shown inthe figure.
Torque: 64N. m
62. Install manual transaxle assembly
63. Install starter assembly
64. Install power steering pump bracket
65. Install power steering pump adjusting bracket with 2 bolts.
66. Connect power steering pump assembly
67. Install engine assembly and transaxle
68. Connect left, right, front and rear lower suspension arm sub-assembly
69. Connect left and right tie rod ball stud pin assembly
70. Connect left, right and front vehicle speed sensor (with ABS)
71. Install left & right nuts on the front shaft hub
72. Install front exhaust pipe assembly
73. Connect steering shaft assembly and steering column hole cover. See (Figure 36)
74. Connect wire harness
75. Install belt adjusting bracket of A/C compressor
76. Connect A/C compressor
77. Install generator assembly
78. Install A/C compressor to crankshaft pulleyV-belt
79. Install generator belt
80. Install engine assembly with transaxle
81. Install radiator assembly
82. Install throttle body assembly
83. Install fuel delivery pipe sub-assembly
84. Install battery
85. Install air filter assembly with hose
86. Install front wheel
87. Fill engine oil
88. Fill coolant
89. Check engine oil for leakage
90. Check engine coolant for leakage
91. Check fuel for leakage
92. Check idle and ignition timing
93. Check CO/HC
94. Check and adjust front wheel alignment
95. Check ABS vehicle speed sensor signalFigure 35
Figure 36
52Chapter 6 Cooling System Inspection
(MR7131A, MR7151A, MR7161A)Section 1 System Check1. Check the cooling system for leakage. See (Figure 118)
(a) Fill coolant into radiator. Install the tester onto the radiator cap port.
(b) Start engine.
(c) The water pump pressure is 118Kpa. Check the pressure and ensure the
pressure will not drop. If the pressure drops, check the port, radiator and
water pump for leakage. If there is no leakage, check the heat exchanger,
cylinder block and cylinder head.
2. Check the engine coolant level in the reservoir.
The coolant level should be between low and full marks.
3. Check coolant quality
(a) Remove radiator cap.
To avoid being scalded, do not remove radiator cap while the engine and
radiator are still hot, as fluid and steam can be sprayed under pressure.
(b) There should not be excessive deposits of rust or scale around the radiator,
and the coolant should be free from oil.
(c) Reinstall the radiator cap.
4. Thermostat
Hint:
The thermostat temp indicates the valve opening temperature.
See (Figure 119).
(a) Immerse the thermostat in water and gradually heat the water.
(b) Check the valve opening temperature. Valve opening temperature: 80 -- 84°C
(c) Check the valve lift. See (Figure 120, Figure 121). Valve lift: 8mm or mor at
95°C
(d) Check the thermostat is fully closed when the thermostat is at low temperature
( 77°C).
5. Radiator cap valve
Standard opening pressure: 93-123kpa
Minimum opening pressure: 78kpa
If the opening pressure is less thanminimum, replace the radiator cap.Figure 118
Figure 119
Figure 120
Figure 121 Radiator Cap Tester8.0mm or
More ≤
536. Fan
(1) Check the cooling fan operation with low temperature (Lower than
83°C)
(a) Turn the ignition switch to “ON” position.
(b) Check that the cooling fan stops.
(c) Pull out the water temperature sensor connector. See (Figure
122)
(d) Connect the water temperature sensor to car body with the
wire and ground the wire.
(e) Check the cooling fan operation.
(f) Insert water temperature sensor connector.> 93°C
See (Figure 123)
(a) Start engine and make the coolant temp. higher than 93°C.
(b) Check that the cooling fan turns.
Replace it with water temperature switch if it doesn't run)
(3) Check the cooling fan. See (Figure 124)
(a) Disconnect the cooling fan connector.
(b) Connect the battery and ammeter to the connector.
(c) Check that the cooling fan rotates smoothly and check
the reading on the ammeter.
Standard amperage: 5.7 - 7.7A
(d) Reconnect the cooling fan connector.Disconnest
Figure 123
Figure 124 Figure 122
(2) Check the cooling fan operation with high temperature (over 93°C)Battery Amperometer
54Section 2 Water Pump, Thermostat and Radiator ReplacementHoist the engine from the compartment. See "Provison 20, Section 2, Chapter 2".
1. Replace water pump. See (Figure 125)
(1) Drain the coolant.
(2) Detach timing belt.
(3) Detach power steering pump assembly.
(4) Remove the oil dipstick guide.
(5) Detach water pump assembly.
(6) Install water pump assembly.
(7) The installation is in the reverse order of the removal.
2. Replace thermostat
(1) Remove thermostat (See Figure 126).
(2) Install thermostat.
a. Install a new gasket to the thermostat. See (Figure 127).
b.Align the main valve of the thermostat to the top of the
stud. Insert the thermostat into the water inlet case.
Hint:
The main valve is set at around 10°C as shown in the figure. See (Figure 128).
(3) Install inlet connector.
Figure 127 Figure 128
3. Replace radiator
(1) Open radiator cap.
(2) Open the drain valve and drain the coolant.
(3) Detach radiator water inlet hose.
(4) Detach radiator water outlet hose.Figure 125
Figure 126
7510. Engine overheat (Table 6)
Table 6Ite m Symptom Trouble shootingRepair or replace
Bad radiator hose Replace
Bad radiator tube strapSupplement welding, otherwise
replace it
Bad cylinder gasket Replace
Cracky cylinder blockRemedy with infiltration technology
or replace it
Poor water pump seal Replace the seal
Replace the anti-freeze liquid
Replace the thermostatBroken we ldSupplement weldingCorrosion result in pin holeFill the pinhole with clear coat,
otherwise replace it
Repair and dredge
Improve the ventilation
Repair or replace the water pump
Troubleshooting, replace the motor if
it is d a ma ge d
Replace
Repair and dredge
Repair or replace the oil pan if there
is o il le a k a ge , r e fill t he o il if it is no t
s up p le me nt e d in t imeCause
Ba d ra diator c over
Clogge d cooling tubePoor ventilationWater
le a ka ge
Anti-fre eze liquid not repla ce d
Bad thermostat
Radiator is
faultyWater
le a ka ge Insufficient
coolantF a ulty fa n vo lta ge
Disabled radiator temperature control
switch
Water jacket is clogged because of too much scale
I ns uffic ie nt e ngine o il ( o il le a k a ge o r d e la ye d filling)P oor
c ooling
Poor FanFaulty water pump
77IV. Exhaust Pipe Discharges Gas with Abnormal Color (or odor)When there is failure in engine combustion system, the exhaust pipe discharges gas with abnormal color.
1. The discharged gas is thickly black
This is caused by incomplete combustion. Since the mixed air is too thick, the combustion is not complete and
part of the fuel is discharged without combustion, leading to decrease of engine power. At this moment, you
should check fuel pressure regulator, throttle position sensor, injector and ECU system and correct the
problems in time.
2. Exhaust is blue and stinks
This is caused by large amount of oil vapor mixed in the exhaust gas that enters in the cylinder and partici-
pates in combustion. One of the primary reasons is that the piston oil ring is dirty and damaged, and shall be
replaced; another reason may be the failure of valve oil seal or excessive clearance between the valve stem
and guide bush hole resulting in oil entering the combustion chamber for combustion, oil seal or valve guide
bush shall be replaced to resume normal condition.
3. Exhaust is white
This is caused by water or fuel vapor mixed in the exhaust. The primary reason is that cylinder head gasket
is damaged, resulting in slow infiltration of coolant into cylinder and the water vapor entry into the exhaust
pipe after combustion, cylinder head gasket shall be replaced to resume the normal condition.Section 3 Engine Noise Diagnosis and TroubleshootingAbnormal sounds generated during engine operation (e.g. knocking sound, chuckle, hiss, rattle) are called
noise.
Engine noise is primarily generated in valve train, connecting rod piston crankshaft components and other
accessory system. The following description discusses the diagnosis and troubleshooting of the noise gener-
ated in valve train and crankshaft connecting rod mechanism.I. Diagnosis and troubleshooting of the noise in valve trainvalve train consists of intake & exhaust camshaft , valve, valve bushing, tappetand counter gear.
1. camshaft noise
(1) camshaft end play is excessively big (normal intake camshaft : 0.030~0.085mm, exhaust camshaft : 0.
035~0.090mm) , when it exceeds 0.11mm and noise is generated, replace it;
(2) Camshaft bend is another cause for noise; it shall be aligned or scraped. ;
(3) Camshaft journal is excessively worn, resulting in big radial clearance between camshaft and bearing and
noise, replace it;
2. Valve group knock noise
(1) Valve noise is caused by excessive valve clearance, the valve spring seat flange is damaged and shall be
replaced;
(2) Valve spring knock noise is caused by broken valve spring. It shall be replaced;