water pump LEXUS SC300 1991 Service User Guide

THERMOSTAT
HINT: Removing the thermostat would decrease the cooling
efficiency. Do not remove the thermostat, even if it tends to
overheat.
COMPONENTS
REMOVAL OF THERMOSTAT
1. DRAIN ENGINE COOLANT (See page CO±5)
2. REMOVE THERMOSTAT (a) Remove the two nuts holding the water inlet to the water
pump, and disconnect the water inlet from the water
pump.
(b) Remove the thermostat.
(c) Remove the gasket from the thermostat.
CO±10
±
COOLING SYSTEM Thermostat
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RADIATOR
CLEANING OF RADIATOR
Using water or a steam cleaner, remove any mud and dirt
from the radiator core.
NOTICE: If using a high pressure type cleaner, be careful
not to deform the fins of the radiator core. If the cleaner
nozzle pressure is 2,942±3,432 kPa (30±35 kgf/cm2,
427±498 psi), keep a distance at least 40±50 cm
(15.75±19.69 in.) between the radiator core and cleaner
nozzle.
INSPECTION OF RADIATOR
1. REMOVE RADIATOR CAP FROM RESERVOIR TANK
2. INSPECT RADIATOR CAPUsing a radiator cap tester, pump the tester and measure the
relief valve opening pressure.
Standard opening pressure:
74±103 kPa
(0.75±1.05 kgf/cm, 10.7±14.9 psi)
Minimum opening pressure:
59 kPa (0.6 kgf/cm, 8.5 psi)
If the opening pressure is less than minimum, replace the ra-
diator cap.
3. INSPECT COOLING SYSTEM FOR LEAKS (a) Fill the radiator with coolant and attach a radiator captester to the reservoir tank.
(b) Warm up the engine.
(c) Pump it to 118 kPa (1.2 kgf/cm2, 17.1 psi), check that pressure does not drop.
If the pressure drops, check for leaks as the hoses, radiator
or water pump. If no external leaks are found, check the heat-
er core, cylinder block and head.
4. REINSTALL RADIATOR CAP
CO±14
±
COOLIING SYSTEM Radiator
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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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ELECTRONICALLY CONTROLLED HYDRAULIC COOLING FAN
Description
In this way system, the cooling fan ECU controls the hydraulic pressure ac\
ting on the hydraulic motor, thus
controlling the speed of the cooling fan steplessly in response to the c\
ondition of the engine and air conditioner.
Operation
The hydraulic pump is driven by a drive belt (V±ribbed belt). The sole\
noid valve adjusts the volume of oil
sent from the hydraulic pump to the hydraulic motor which drives the fan dir\
ectly, thereby controlling the fan
speed. Oil which has passed through the hydraulic motor is cooled by the oil coole\
r before returning to the reservoir
tank. The solenoid valve is controlled by the computer in accordance with the E/G\
rpm, water temp. and A/C
signals. CO±22
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Description, Operation)
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10. REMOVE LH ENGINE WIRE COVERRemove the two bolts and engine wire cover.
11. REMOVE VSV FOR EVAP SYSTEM Remove the two bolts, and disconnect the VSV from cylinder
head and timing belt cover.
12. REMOVE RH NO.3 TIMING BELT COVER Remove the three bolts and timing belt cover.
13. REMOVE LH NO.3 TIMING BELT COVER (a) Remove the four mounting bolts.
(b) Disconnect the cord grommet from the timing belt cover,
and remove the timing belt cover.
(c) Remove the cord grommet from the high±tension cord.
14. DISCONNECT RADIATOR HOSE FROM WATER INLET
15. REMOVE DRIVE BELT IDLER PULLEY Remove the pulley bolt, cover plate and idler pulley.
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)CO±29
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5. INSTALL DRIVE BELT IDLER PULLEYInstall the idler pulley and cover plate with the pulley bolt.
Torque: 37 N Vm (380 kgf Vcm, 27 ft Vlbf)
6. CONNECT RADIATOR HOSE TO WATER INLET
7. INSTALL RH NO.3 TIMING BELT COVER
(a) Install the three gaskets to the timing belt cover.
(b) Fit portion A of the timing belt cover, matching it with the
lower high±tension cord cover.
(c) Install the timing belt cover with the three bolts.
8. INSTALL VSV FOR EVAP SYSTEM Install the VSV with the two bolts.
9. INSTALL LH NO.3 TIMING BELT COVER (a) Install the three gaskets to the timing belt cover.
(b) Install the cord grommet to the high±tension cord.
(c) Install the cord grommet to the timing belt cover.
(d) Fit portion A of the timing belt cover, matching it with the
lower high±tension cord cover.
(e) Install the timing belt cover with the four bolts.
10. INSTALL RH ENGINE WIRE COVER (a) Fit portions A and B of the engine wire cover, matchingthem with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the bolt.
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Pump)CO±43
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14. INSTALL IGNITION COIL(a) Install the ignition coil with the two bolts.
(b) Connect the following connectors and cord:(1) Ignition coil connector
(2) Noise filter connector
(3) High±tension cord
15. INSTALL A/C COMPRESSOR (a) In sta ll th e A/C co mp re sso r, co mp re sso r sta y an dground cable with the three bolts and nut.
Torque: Bolt 49 N Vm (500 kgf Vcm, 36 ft Vlbf)
Nut 29 N Vm (300 kgf Vcm, 22 ft Vlbf)
(b) Connect the A/C compressor connector.
16. INSTALL DRIVE BELT Install the drive belt by turning the drive belt tensioner coun-
terclockwise.
HINT: The pulley bolt for the belt tensioner has a left±hand
thread.
17. CONNECT RADIATOR HOSE TO WATER INLET
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Pump)CO±45
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Crankshaft Thrust clearance STD 0.020±0.220 mm (0.0008±0.0087 in.)
   Limit 0.30 mm (0.0118 in.)
  Thrust washer thickness  2.440±2.490 mm (0.0961±0.0980 in.)
  Main journal bore diameter on cylinder block  67.026±67.033 mm (2.8388±2.6391 in.)  
(with main bearing)
  
  
Main journal oil clearance
 
STD
 
0.026±0.045 mm (0.0010±0.0018 in.)   Limit 0.055 mm (0.0022 in.)  Main journal diameter  66.988±67.000 mm (2.6373±2.6378 in.) \
 \
Main bearing center wall thickness (Reference) 
   Mark 1 2.486±2.489 mm (0.0979±0.0980 in.)   Mark 2 2.489±2.492 mm (0.0980±0.0981 in.)   Mark 3 2.492±2.495 mm (0.0981±0.0982 in.)   Mark 4 2.495±2.498 mm (0.0982±0.0983 in.)
   Mark 5 2.498±2.501 mm (0.0983±0.0985 in.)
  Crank pin diameter  51.982±52.000 mm (2.0465±2.0472 in.)
  Circle runout Limit 0.08mm (0.0031 in.)
  Main journal taper and out±of±round Limit 0.02mm (0.0008 in.)
  Crank pin taper and out±of±round Limit 0.02mm (0.0008.in)
EGOC6±0C
TORQUE SPECIFICATION
 Part tightened  NVm kgf Vcm ft Vlbf
 No.1 idler pulley x Cylinder Block  34 350 25
 No.2 idler pulley x Cylinder block3435025
 Hydraulic pump x Cylinder block for 12 mm head 16 160 12

yy
for 14 mm head3031022 Crankshaft pulley x Crankshaft  245 2,500 181 Camshaft timing pulley x Camshaft  108 1,100 80 Timing belt tensioner x Oil pump  26 270 20 Spark plug x Cylinder head  18 180 13
 Drive belt tensioner x Cylinder block  16 160 12
 Generator x Generator bracket  37 380 27
 Generator x Cylinder block3738027
 Distributor housing x Cylinder head1818513
 Distributor rotor x Camshaft timing pulley3.83934 in.
lbf
 Distributor cap x Distributor housing3.83934 in.
lbf
 RH No.2 timing belt cover x Cylinder blockfor 12 mm head1818513
Drive belt idler pulley x Fan bracket3738027 
A/C compressor x Cylinder block4950036 A/C compressor x Fan bracket  49 500 36 A/C compressor stay x Oil filter bracket  29 300 22 Upper radiator support x Body  12 120 9 Exhaust manifold x Cylinder head  44 450 33
 Cylinder head x Cylinder block 1st 39 400 29
  2nd Turn 90 5  
 Camshaft bearing cap x Cylinder head  16 160 12
 Cylinder head cover x Cylinder head  5.9 60 52 in.Vlbf
Engine hanger x Cylinder head3738027 EGR pipe x RH exhaust pipe  18 185 13 Rear water bypass joint x Cylinder head  18 185 13
±
1UZ ± FE ENGINE ENGINE MECHANICALEG±209
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Front water bypass joint x Cylinder head  18 185 13
 Intake manifold x Cylinder head1818513
Delivery pipe x Intake manifold1818513 
Fuel return pipe x Fuel pressure regulator
  
35
 
360
 
26 Fuel inlet hose x Delivery pipe  39 400 29  for SST 33 340 24 Cold start injector x Air intake chamber  7.8 80 69 in.Vlbf Air intake chamber x Intake manifold  18 185 13 EGR pipe x Air intake chamber  18 185 13
 EGR pipe x RH cylinder head  18 185 13
 Cold start injector tube x Air intake chamber  15 150 11
 Union (for brake booster) x Air intake chamber  29 300 22
 Throttle body x Air intake chamber  18 185 13
 IAC valve x Air intake chamber  18 185 13
 EGR valve adaptor x Air intake chamber  18 185 13
 EGR valve x EGR valve adaptor  18 185 13
Timing belt rear plate x Cylinder head7.88069 in. Vlbf 
Water outlet housing x Water pump
  
18
 
185
 
13 Main bearing stud bolt x Cylinder block  15 150 11 Main bearing cap x Cylinder block for nut (1st) 27 275 20  (2nd) Turn 90 5  
  for bolt 49 500 36 Connecting rod cap x Connecting rod 1st 25 250 18
  2nd Turn 905  
 Rear oil seal retainer x Cylinder block  7.8 80 69 in.Vlbf
 Water seal plate x Cylinder block  14 145 10
 Generator bracket x Cylinder block  18 185 13
 Oil pump x Cylinder block 12 mm head 16 160 12
  14 mm head 30 310 22
 No.1 oil pan x Cylinder block 10 mm head 7.8 80 69 in. Vlbf
12 mm head1818513 
No.1 oil pan x Oil pump
  
7.8
 
80
 
69 in. Vlbf No.1 oil pan x Rear oil seal retainer  7.8 80 69 in. Vlbf Oil strainer x Cylinder block  7.8 80 69 in. Vlbf Oil strainer x Oil pump  7.8 80 69 in. Vlbf Oil pan baffle plate x No.1 oil pan  7.8 80 69 in. Vlbf No.1 oil pan x No.2 oil pan  7.8 80 69 in. Vlbf
 Water pump x Cylinder block  18 185 13
 Water bypass pipe x Cylinder Block  18 185 13
 Knock sensor x Cylinder block  44 450 33
 Starter x Cylinder block  39 400 29
 Engine mounting bracket x Cylinder block  37 380 27
 Drive plate x Crankshaft  98 1,000 72
 Transmission x Cylinder block  57 580 42
 Transmission x No.1 oil pan  39 400 29
Drive plate x Torque converter3334025 Transmission oil cooler pipe x Transmission for union nut 34 350 25 Rear engine mounting member x Body  25 250 19\
 \
Rear engine mounting member x Rear engine mounting insulator1313510
EG±210±
1UZ ± FE ENGINE ENGINE MECHANICAL
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The 1 UZ±FE engine has 8±cylinders in a V±arrangement at a bank an\
gle of 905. From the front of the RH
bank cylinders are numbered 2 ± 4 ± 6 ± 8, and from the front of t\
he LH bank cylinders are 1 ± 3 ± 5 ± 7.
The crankshaft is supported by 5 bearings inside the crankcase. These beari\
ngs are made of a copper and
lead alloy.
The crankshaft is integrated with 8 weights for balance. Oil holes are plac\
ed in the center of the crankshaft
to supply oil to the connecting rods, bearing, pistons and other component\
s.
The ignition order is 1 ± 8 ± 4 ± 3 ± 6 ± 5 ± 7 ± 2. T\
he cylinder head is made of alminum alloy, with a cross
flow type intake and exhaust layout and with pent±roof type combustion chambers. The spark plugs are
located in the center of the combustion chambers.
At the front and rear of the intake manifold, a water passage has been p\
rovided which connects the RH
and LH cylinder heads.
Exhaust and intake valves are equipped with irregular pitch springs made\
of special valve spring carbon
steel which are capable of functioning at all engine speeds.
The RH and LH intake camshaft are driven by a timing belt, and a gear on\
the intake camshaft engages
with a gear on the exhaust camshaft to drive it. The cam journal is supp\
orted at 5 (intake) or 4 (exhaust)
places between the valve lifters of each cylinder and on the front end o\
f the cylinder head. Lubrication of
the cam journals and gears is accomplished by oil being supplied through th\
e oiler port in the center of the
camshaft.
Adjustment of the valve clearance is done by means of an outer shim type\
system, in which valve adjusting
shims are located above the valve lifters. This permits replacement of the sh\
ims without removal of the
camshafts.
Pistons are made of high temperature±resistant aluminum alloy, and a depression is built into the piston
head to prevent interference with the valves.
Piston pins are the full±floating type, with the pins fastened to neither the piston boss nor the connecting
rods. Instead, snap rings are fitted on both ends of the pins, preventing the\
pins from falling out.
The No.1 compression ring is made of steel and the No.2 compression ring\
is made of cast iron. The oil
ring is made of a combination of steel and stainless steel. The outer diamet\
er of each piston ring is slightly
larger than the diameter of the piston and the flexibility of the rings allows them to hug the cylinder walls
when they are mounted on the piston. Compression rings No.1 and No.2 work to\
prevent gas leakage from
the cylinder and the oil ring works to scrape oil off the cylinder walls to prevent it from entering the combus-
tion chambers.
The cylinder block is made of aluminum alloy with a bank of 90 5. Cast iron cylinders are installed inside
the cylinder block. It has 8 cylinders which are approximately twice the le\
ngth of the piston stroke. The top
of each cylinder is closed off by the cylinder head and the lower end of the cylinders becomes the crank-
case, in which the crankshaft is installed. In addition, the cylinder block c\
ontains a water jacket, through
which coolant is pumped to cool the cylinders.
The No.1 and No.2 oil pans are bolted onto the bottom of the cylinder bl\
ock. The No.1 oil pan is made of
aluminum alloy. The No.2 oil pan is an oil reservoir made of pressed steel sheet. An o\
il level sensor is
installed in the No.1 oil pan (If oil level drops below a set level, a warning light\
s up.). And oil pan baffle plate
keeps sufficient oil in the bottom of the No.2 oil pan even when the vehicle is t\
ilted. This dividing plate also
prevents the oil from marking waves when the vehicle is stopped suddenly\
and the oil shifts away from the
oil pump suction pipe.
Plastic region tighten bolts are used for the cylinder head, main bearin\
g cap and connecting rod.
EG±4
±
1UZ±FE ENGINE ENGINE MECHANICAL
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