engine coolant LEXUS SC400 1991 Service Owner's Manual

9. FILL ENGINE WITH COOLANT (See page CO±7)
10. FILL COOLING FAN RESERVOIR TANK WITH FLUID (See pages CO±23 and 24)
11. CHECK AUTOMATIC TRANSMISSION FLUID LEVEL
(See page MA±11)
NOTICE: Do not overfill.
12. START ENGINE AND CHECK FOR LEAKS
13. INSTALL ENGINE UNDER COVER
±
COOLIING SYSTEM RadiatorCO±21
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(3) Upper radiator hose or radiator
(4) Reservoir hose to radiator
5. INSTALL BATTERY
6. FILL ENGINE WITH COOLANT (See page CO±5)
Capacity (w/ Heater):
M/T 8.5 liters (9.0 US qts, 7.5 Imp. qts)
A/T 8.4 liters (8.9 US qts, 7.4 Imp. qts)
7. (A/T)
CHECK AUTOMATIC TRANSMISSION FLUID LEVEL (See pageMA±11 )
NOTICE: Do not overfill.
8. START ENGINE AND CHECK FOR LEAKS
9. INSTALL ENGINE UNDER COVER
SERVICE SPECIFICATIONS
SERVICE DATA
ThermostatValve opening temperature80±84 5c176±183 5F
Valve liftat 95 5C (203 5F) 8.5 mm0.335 in.
Radiator capRelief valve opening pressureSTD74±103 kPa
(0 75 1 05 k f/ 10 7 14 9 i)(0.75±1.05 kgf/cm, 10.7±14.9 psi)
Limit59 kPa0.6 kgf/cm28.5 psi
TORQUE SPECIFICATIONS
Part tightenedN
mkgf
cmft
lbf
Engine drain plug X Cylinder block2930022
Water pump X Cylinder block2121015
Water pump X Water by±pass pipe2121015
Water by±pass outlet X Cylinder head 8.89078 in.
lbf
Water inlet X Water pump 8.89078 in.
lbf
Oil cooler X Radiator lower tank (A/T) 8.38574 in.
lbf
Oil cooler X Pipe (A/T)1515011
Radiator fan shroud X Radiator 4.95043 in.
lbf
Radiator X Body121209
±
COOLING SYSTEM Radiator, Service SpecificationsCO±21
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REMOVAL OF HYDRAULIC PUMP
(See Components on page CO±26)
1. REMOVE BATTERY CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE ENGINE UNDER COVER
3. DRAIN ENGINE COOLANT (See page CO±6)
4. REMOVE DRIVE BELT Loosen the drive belt tension by turning the drive belt tension-
er counterclockwise, and remove the drive belt.
HINT: The pulley bolt for the belt tensioner has a left±hand
thread.
5. DISCONNECT A/C COMPRESSOR (a) Disconnect the A/C compressor connector.
(b) Remove the nut, and disconnect the ground cable.
(c) Remove the bolt and A/C compressor stay.
(d) R e m o v e t h e t w o b o l t s , a n d d i s c onnect the A/C
compressor from the engine.
6. REMOVE LH IGNITION COIL (a) Disconnect the following connectors and cord:(1) Ignition coil connector
(2) Noise filter connector
(3) High±tension cord
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)CO±27
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18. INSTALL BATTERY
19. FILL ENGINE WITH COOLANT (See page CO±7)
20. FILL COOLING FAN RESERVOIR TANK WITH FLUID (See pages CO±23 and 24)
21. START ENGINE AND CHECK FOR LEAKS
22. INSTALL ENGINE UNDER COVER
CO±46
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Pump)
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REMOVAL OF HYDRAULIC MOTOR
(See Components on page CO±47)
1. REMOVE BATTERY CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE ENGINE UNDER COVERS
3. DRAIN ENGINE COOLANT (See page CO±6)
4. REMOVE RADIATOR RESERVOIR TANK (a) Disconnect the coolant level sensor connector.
(b) Disconnect the following hoses:(1) Reservoir hose from water inlet housing
(2) Reservoir hose from radiator
(c) Remove the two bolts and reservoir tank bracket.
(d) Disconnect the reservoir tank from the reservoir tank bracket, and remove the reservoir tank.
5. DISCONNECT HOSES Disconnect the following hoses:(1) Upper radiator hose from radiator
(2) Pressure hose from hydraulic motor
(3) Return hose from hydraulic motor
CO±48
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)
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7. INSTALL RADIATOR RESERVOIR TANK(a) Install the reservoir tank to the reservoir tank bracket.
(b) Install the reservoir tank bracket with two bolts.
Torque: 4.9 N Vm (50 kgf Vcm, 43 in. Vlbf)
(c) Connect the following hoses:
(1) Reservoir hose to water inlet housing
(2) Reservoir hose to radiator
(d) Connect the coolant level sensor connector.
8. INSTALL BATTERY
9. FILL ENGINE WITH COOLANT (See page CO±7)
10. FILL COOLING FAN RESERVOIR TANK WITH FLUID
(See pages CO±23 and 24)
11. START ENGINE AND CHECK FOR LEAKS
12. INSTALL ENGINE UNDER COVER
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)CO±57
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(Water Temperature Sensor)
COMPONENTS FOR REMOVAL AND
INSTALLATION
INSPECTION OF WATER TEMPERATURE
SENSOR
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after 20 seconds or
longer from the time the ignition switch is turned to the
ºLOCKº position and the negative (±) terminal cable is
disconnected from the battery.
2. REMOVE ENGINE UNDER COVER
3. DRAIN ENGINE COOLANT (See page CO±6)
4. REMOVE WATER TEMPERATURE SENSOR (a) Disconnect the water temperature sensor connector.
(b) Remove the water temperature sensor from left side ofthe radiator lower tank.
(c) Remove the O±ring from the water temperature sensor.
CO±62
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)
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5. INSPECT WATER TEMPERATURE SENSORUsing an ohmmeter, measure the resistance between the ter-
minals.
Resistance: 1.48±1.58 k
at 80 5C (176 5F)
If the resistance is not as specified, replace the sensor.
6. REINSTALL WATER TEMPERATURE SENSOR (a) Install a new O±ring to the water temperature sensor.
(b) Apply soapy water to the O±ring.
(c) Install the water temperature sensor to the radiator.
Torque: 7.4 N Vm (75 kgf Vcm, 65 in. Vlbf)
(d) Connect the water temperature sensor connector.
7. REFILL WITH ENGINE COOLANT (See page CO±7)
8. REINSTALL ENGINE UNDER COVER
9. RECONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
(A/C High±Pressure Switch)
INSPECTION OF A/C HIGH±PRESSURE
SWITCH
1. DISCONNECT HIGH±PRESSURE SWITCH CONNECTOR
2. INSTALL MANIFOLD GAUGE SET (See AC section)
3. INSPECT HIGH±PRESSURE SWITCH(a) Wh e n th e A/C switch is OFF, ch e ck th a t th e re iscontinuity between terminals 2 and 3. (When the
pressure is 1,226 kPa (12.5 kgf/cm
2, 178 psi) or lower.)
(b) When the A/C switch and blower switch are ON, check
that there is no continuity between terminals 2 and 3.
(When the pressure is 1,520 kPa (15.5 kgf/cm
2, 220 psi)
or higher.)
If continuity is not as specified, replace the switch.
4. REMOVE MANIFOLD GAUGE SET
5. RECONNECT HIGH±PRESSURE SWITCH CONNECTOR
(Solenoid Valve)
(See page CO±36)
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Electronic Control Parts)CO±63
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(e) Check whether the engine rpm increases 100±300 rpmunder the following conditions:
Coolant temp.
Below 45 5C (113 5F) . . . NO increase
Above 50 5C (122 5F) . . . Increases
INSPECTION OF VSV
1. REMOVE VSV
(a) Disconnect the VSV connector.
(b) Disconnect the two vacuum hoses from VSV.
(c) Remove the bolt and VSV from the intake manifold.
2. INSPECT VSV (a) Inspect VSV for open circuit.Using an ohmmeter, check that there is continuity be-
tween the terminals.
Resistance (Cold): 33±39

If there is no continuity, replace the VSV.
(b) Inspect VSV for ground.
Using an ohmmeter, check that there is no continuity be-
tween each terminal and the body.
If there is continuity, replace the VSV.
(c) Inspect VSV operation: 1) Check that the air flows from ports E to G
±
EMISSION CONTROL SYSTEMS Exhaust Gas Recirculation (EGR) SystemEC±13
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EXHAUST GAS RECIRCULATION (EGR) SYSTEM
DESCRIPTION
To reduce NOx emission, part of the exhaust gases are recirculated through\
the EGR valve to the intake
manifold to lower the maximum combustion temperature.
OPERATION
Coolant Temp.ConditionEGR ValveExhaust Gas
Below 53 5C (127 5F)±CLOSEDNot recirculated
Above 55 5C (131 5F)(a)Idling, Deceleration, Neutral,
Low air volume, High Engine speedCLOSEDNot recirculatedAbove 55 C (131 F)
Except (a)OPEN*Recirculated
* The ECU calculates the appropriate number of steps according to the in\
take air volume and the engine speed, then
drives the stepping motor to maintain the EGR volume at a level appropri\
ate to the driving conditions.

±
EMISSION CONTROL SYSTEMS Exhaust Gas Recirculation (EGR) SystemEC±15
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