ect LEXUS SC300 1991 Service Repair Manual

(c) Check the ignition timing.
Ignition timing: 8±125 BTDC @ idle
(Transmission in neutral range)
If the ignition timing is not as specified, check that following
conditions are normal: w Throttle valve fully closed
w Continuity between terminals IDL1 and E2 of the
throttle position sensor (See page FI±73)
w Valve timing (See page EM±51)
(e) Remove the SST from the check connector.
SST 09843±18020
17. DISCONNECT TACHOMETER AND TIMING LIGHT FROM ENGINE
18. INSTALL UPPER HIGH±TENSION CORD COVER (See step 10 on pages IG±18 and 19)
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IGNITION SYSTEM DistributorIG±29
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A pressure feeding lubrication system has been adopted to supply oil to \
the moving parts of this engine. The
lubrication system consists of an oil pan, oil pump, oil filter and other external p\
arts which supply oil to the moving
parts in the engine block. The oil circuit is shown in the illustration at th\
e top of the previous page. Oil from the
oil pan is pumped up by the oil pump. After it passes through the oil fi\
lter, it is fed through the various oil holes
in the crankshaft and cylinder block. After passing through the cylinder b\
lock and performing its lubricating func-
tion, the oil is returned by gravity to the oil pan. A dipstick on the center\
left side of the cylinder block is provided
to check the oil level.
OIL PUMP The oil pump pumps up oil from the oil pan and sends it under pressure to t\
he various parts of the engine.
An oil strainer is mounted in front of the inlet to the oil pump. The oil \
pump itself is a trochoid type pump, inside
of which there is a drive rotor and a driven rotor. When the drive rotor rotates, the driven rotor rotates in the same
direction, and since the axis of the driven rotor shaft is different from the center of the driven rotor, the space
between the two rotors is changed as they rotate. Oil is drawn in when the space\
is wide and is discharged when
the space in narrow.
OIL PRESSURE REGULATOR At high engine speeds, the engine oil supplied by the oil pump exceeds the\
capacity of the engine to utilize
it. For that reason, the oil pressure regulator works to prevent an over\
supply of oil. During normal oil supply, a
coil spring and valve keep the bypass closed, but when too much oil is being \
fed, the pressure become extremely
high, overpowering the force of the spring and opening the valves. This allow\
s the excess oil to flow through
the valve and return to the oil pump inlet.
OIL FILTER The oil filter is a full flow type filter with a built±in paper filter e\
lement. Particles of metal from wear, airborne
dirt, carbon and other impurities can get into the oil during use and co\
uld cause accelerated wear or seizing if
allowed to circulate through the engine. The oil filter, integrated into the oil line, removes these impurities as the
oil passes through it. The filter is mounted outside the engine to simplify\
replacement of the filter element. A relief
valve is also included ahead of the filter element to relieve the high oil pr\
essure in case the filter element be-
comes clogged with impurities. The relief valve opens when the oil pressure o\
verpowers the force of the spring.
Oil passing through the relief valve by±passes the oil filter and flo\
ws directly into the main oil hole in the engine.
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LUBRICATION SYSTEM PrecautionsLU±3
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OIL PRESSURE CHECK
1. CHECK ENGINE OIL QUALITYCheck the oil for deterioration, presence of water, discoloring
or thinning.
If the quality is poor, replace the oil.
Oil grade: API grade SG, Energy±Conserving II multigrade.
Recommended viscosity is as shown, with SAE 5W±30 being
the preferred engine oil.
2. CHECK ENGINE OIL LEVELThe oil level should be between the ºLº and ºFº marks on the
dipstick.
If low, check for the leakage and add oil up to ºFº mark.
3. REMOVE ENGINE UNDER COVER
4. REMOVE DRIVE BELT Loosen the drive belt tension by turning the drive belt tension-
er clockwise, and remove the drive belt.
5. DISCONNECT A/C COMPRESSOR WITHOUT DISCONNECTING HOSES
(a) Disconnect the compressor connector.
(b) Remove the four mounting bolts and nut.
(c) R e m o v e t h e t h r ought bolt, and disconnect the
compressor from the engine.
HINT: Put aside the compressor, and suspend it.
6. REMOVE OIL PRESSURE SWITCH, AND INSTALL OIL PRESSURE GAUGE
(a) Disconnect the oil pressure switch connector.
(b) Using SST, remove the oil pressure switch.SST 09816±30010
(c) Install an oil pressure gauge.
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LUBRICATION SYSTEM Oil pressure CheckLU±5
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7. REINSTALL A/C COMPRESSOR(a) Install the A/C compressor with the through bolt, fourbolts and nut.
Torque:
Through bolt 26 N Vm (265 kgf Vcm, 19 ft Vlbf)
Bolt and nut 52 N Vm (530 kgf Vcm, 38 ft Vlbf)
(b) Connect the compressor connector.
8. REINSTALL DRIVE BELT Install the drive belt by turning the drive belt tensioner clock-
wise.
9. WARM UP ENGINE Allow the engine to warm up to normal operating
temperature.
10. CHECK OIL PRESSURE
Oil pressure:
At idle speed 29 kPa (0.3 kgf/cm
, 4.3 psi)
or more
At 3,000 rpm 294±539 kPa (3.0±5.5 kgf/cm
, 78 psi)
11. REMOVE DRIVE BELT (See step 4)
12. DISCONNECT A/C COMPRESSOR FROM ENGINE
(See step 5)
13. REMOVE OIL PRESSURE GAUGE AND REINSTALL OIL PRESSURE SWITCH
(a) Remove an oil pressure gauge.
(b) A p p ly a dhesive to two or three threads of the oil
pressure switch.
Adhesive: Part No. 08833±00080, THREE BOND 1344,
LOCTITE 242 or equivalent
(c) Using SST, install the oil pressure switch.
SST 09816±30010
Torque: 14 NVm (150 kgf Vcm, 11 ft Vlbf)
(d) Connect the compressor connector.
14. REINSTALL A/C COMPRESSOR (See step 7)
15. REINSTALL DRIVE BELT (See step 8)
16. START ENGINE AND CHECK FOR LEAKS
17. REINSTALL ENGINE UNDER COVER
LU±6
±
LUBRICATION SYSTEM Oil pressure Check
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REPLACEMENT OF ENGINE OIL
AND OIL FILTER
CAUTION:
wProlonged and repeated contact with mineral oil will
result in the removal of natural fats from the skin, leading
to dryness, irritation and dermatitis. In addition, used
engine oil contains potentially harmful contaminants
which may cause skin cancer.
w Exerise caution in order to minimize the length and
frequency of contact of your skin to used oil. Wear
protective clothing and gloves. The skin s hould be
thoroughly w ashed with soap and water, or use waterless
hand cleaner, to remove any used engine oil. Do not use
gasoline, thinners, or solvents.
w In order to preserve the environment, used oil and used
oil filter must be disposed of only at designated disposal
sites.
1. DRAIN ENGINE OIL
(a) Remove the oil filler cap.
(b) Remove the oil drain plug, and drain the oil into acontainer.
2. REPLACE OIL FILTER (a) Using SST, remove the oil filter.
SST 09228±07500
(b) Check and clean the oil filter installation surface.
(c) Apply clean engine oil to the gasket of a new oil filter.
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LUBRICATION SYSTEM Replacement of Engine Oil and Oil FilterLU±7
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REMOVAL OF OIL PUMP
(See Components on page LU±8)
HINT: When repairing the oil pump, the oil pan and strainer
should be removed and cleaned.
1. REMOVE ENGINE WITH TRANSMISSION (See pages EM±118 to 128)
2. SEPARATE ENGINE AND TRANSMISSION (See pages EM±129 to 130)
3. INSTALL ENGINE TO ENGINE STAND FOR REMOVAL
4. REMOVE TIMING BELT (See steps 8 to 35 on pages EM±36 to 43)
5. REMOVE NO.2 IDLER PULLEY, NO.1 IDLER PULLEY AND CRANKSHAFT TIMING PULLEY
(See steps 36 to 38 on page EM±44)
6. REMOVE OIL DIPSTICK AND GUIDE (a) Remove the mounting bolt.
(b) Pull out the dipstick guide together with dipstick guide.
(c) Remove the O±ring from the dipstick guide.
7. REMOVE BRACKET OF MAIN OXYGEN SENSOR CONNECTOR FROM NO.1 OIL PAN
Remove the bolt, and disconnect the connector bracket.
8. REMOVE OIL LEVEL SENSOR (a) Disconnect the level sensor connector.
(b) Remove the four mounting bolts, and disconnect theengine wire bracket.
(c) Remove the level sensor.
(d) Remove the gasket from the level sensor.
9. REMOVE NO.2 OIL PAN (a) Remove the twelve mounting bolts and two nuts.
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LUBRICATION SYSTEM Oil PumpLU±9
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12. REMOVE OIL STRAINERRemove the two bolts, two nuts, oil strainer and gasket.
13. REMOVE OIL FILTER BRACKET (a) Disconnect the oil pressure switch connector.
(b) Remove the two bo lts, stud bolt, the filter bracket and oil
filter assembly.
(c) Remove the gasket from the filter bracket.
14. REMOVE ENGINE SPEED SENSOR (a) Disconnect the speed sensor connector.
(b) Remove the bolt and speed sensor.
15. REMOVE OIL PUMP (a) Remove the eight mounting bolts.
(b) Remove the oil pump by prying the portions between the
cylinder block and oil pump with a screwdriver.
NOTICE: Be careful not to damage the contact surfaces
of the cylinder block and oil pump.
(c) Remove the O±ring from the cylinder block.
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LUBRICATION SYSTEM Oil PumpLU±11
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INSPECTION OF OIL PUMP
1. INSPECT RELIEF VALVECoat the valve with engine oil and check that it falls smoothly
into the valve hole by its own weight.
If it doesn't, replace the relief valve. If necessary, replace the
oil pump assembly.
2. INSPECT DRIVE AND DRIVEN ROTORS
A. Place drive and driven rotors into oil pump body Face the mark of the rotors upward.
B. Inspect rotor tip clearance Using a feeler gauge, measure the clearance between the
drive and driven rotors.
Standard tip clearance: 0.110±0.240 mm
(0.0043±0.0094 in.)
Maximum tip clearance: 0.35 mm (0.0138 in.)
If the tip clearance is greater than maximum, replace the ro-
tors as a set.
C. Inspect rotor side clearance Using a feeler gauge and precision straight edge, measure
the clearance between the rotors and precision straight
edge.
Standard side clearance: 0.030±0.090 mm
(0.0012±0.0035 in.)
Maximum side clearance: 0.15 mm (0.0059 in.)
If the side clearance is greater than maximum, replace the ro-
tors as a set. If necessary, replace the oil pump assembly.
D. Inspect rotor body clearance Using a feeler gauge, measure the clearance between the
driven rotor and pump body.
Standard body clearance: 0.100±0.175 mm
(0.0039±0.0069 in.)
Maximum body clearance: 0.30 mm (0.0118 in.)
If the body clearance is greater than maximum, replace the
rotors as a set. If necessary, replace the oil pump assembly.
E. Remove drive and driven rotors
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LUBRICATION SYSTEM Oil PumpLU±13
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INSTALLATION OF OIL PUMP
(See Components on page LU±8)
1. INSTALL OIL PUMP (a) Remove any old packing (FIPG) material and be careful
not to drop any oil on the contact surfaces of the oil
pump cylinder block.
w Using a razor blade and gasket scraper, remove all
the old packing (FIPG) material from the gasket
surfaces and sealing groove.
w Thoroughly clean all components to remove all the
loose material.
w Using a non±residue solvent, clean both sealing
surfaces.
NOTICE: Do not use a solvent which will affect the
painted surfaces.
(b) Apply seal packing to the oil pump as shown in the illustration.
Seal packing: Part No. 08826±00080 or equivalent
w Install a nozzle that has been cut to a 2±3 mm
(0.08±0.12 in.) opening.
HINT: Avoid applying an excessive amount to the surface. Be
particularly careful near oil passages.
w Parts must be assembled within 5 minutes of
application. Otherwise the material must be
removed and reapplied.
w Immediately remove nozzle from the tube and
reinstall cap.
(c) Place a new gasket in position on the cylinder block.
(d) Engage the spline teeth of the oil pump drive rotor with the large teeth of the crankshaft, and slide the oil pump.
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LUBRICATION SYSTEM Oil PumpLU±15
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(e) Install the oil pump with the eight bolts.
Torque:12 mm head 16 N Vm (160 kgf Vcm, 12 ft Vlbf)
14 mm head 30 N Vm (310 kgf Vcm, 22 ft Vlbf)
HINT: Each bolt length is indicated in the illustration.
Bolt length:
A 50 mm (1.97 in.) for 12 mm head
B 106 mm (4.17 in.) for 12 mm head
C 30 mm (1.18 in.) for 12 mm head
D 40 mm (1.57 in.) for 14 mm head
2. INSTALL ENGINE SPEED SENSOR (a) Install the speed sensor with the bolt.
Torque: 6.4 N Vm (65 kgf Vcm, 56 in. Vlbf)
(b) Connect the speed sensor connector.
3. INSTALL OIL FILTER BRACKET (a) Place a new gasket in position on the oil filter bracket.
(b) Install the oil filter bracket with the two bolts and studbolt.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
(c) Connect the oil pressure switch connector.
4. INSTALL OIL STRAINER Install a new gasket and the oil strainer with the two bolts and
two nuts.
Torque: 7.8 N Vm (80 kgf Vcm, 69 in. Vlbf)
LU±16±
LUBRICATION SYSTEM Oil Pump
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