1991 LEXUS SC300 oil pressure

SERVICE SPECIFICATIONS
SERVICE DATA
 Engine tune±up Battery specific gravity  1.27±1.29 g  (when fully charged at 205C (68 5F))  High±tension cord resistance Limit 25 k
per cord  Valve clearance Intake 0.15 ± 0.25 mm 0.006 ± 0.010 in.   Exhaust 0.25 ± 0.35 mm 0.010 ± 0.014 in.
  Ignition timing 8±12 5 BTDC @ idle
   (w/ Terminals TE1 and E1 connected)
  Idle speed 700 + 50 rpm
 


Intake
manifold 


at Idle speed 


 


60 kPa 450 mmHg 17.7 in.Hg
vacuum vacuum  
Compressionat 250 rpmSTD1,226 kPa (12.5 kgf/cm, 178 psi) or more pressure  Limit 981 kPa 10.0 kgf/cm 142 psi  Difference of pressure between each cylinder 98 kPa (1.0 kgf/cm, 14 psi) or less Timing belt ten- Protrusion from housing end 10.5 ± 11.5 mm 0.413 ± 0.453 in. g
sioner g  
 Cylinder head Warpage Cylinder block side Limit 0.10 mm 0.0039 in.
 
y
 Manifold side Limit 0.10 mm 0.0039 in.
  Valve seat Refacing angle 30
5, 45 5, 75 5
  Contacting angle 455
Contacting width1.0 ± 1.4 mm0.039 ± 0.055 in.  Cylinder head bolt thread outside diam4eter 
   STD 9.770 ± 9.960 mm 0.3846 ± 0.3921 in.   Limit 9.60 mm 0.3780 in. Valve guide Inside diameter 6.010 ± 6.030 mm 0.2366 ± 0.2374 in.
 
g
bushing Outside diameter (for repair part) STD 11.048 ± 11.059 mm 0.4350 ± 0.4354 in.
 
g
  O/S 0.05 11.098 ± 11.109 mm 0.4369 ± 0.4374 in.
 Valve Valve overall length STD Intake 94.95 mm 3.7382 in.
    Exhaust 96.90 mm 3.8150 in.
LimitIntake94.45 mm3.7185 in.    Exhaust 96.40 mm 3.7953 in.  Valve face angle   44.5 5  Stem diameter  Intake 5.970 ± 5.985 mm 0.2350 ± 0.2356 in.    Exhaust 5.965 ± 5.980 mm 0.2356 ± 0.2354 in.
  Stem oil clearance STD Intake 0.025 ± 0.060 mm 0.0010 ± 0.0024 in.
    Exhaust 0.030 ± 0.065 mm 0.0012 ± 0.0026 in.
   Limit Intake 0.08 mm 0.0031 in.
Exhaust0.10 mm0.0039 in.  Margin thickness  STD 1.0 mm 0.039 in.    Limit 0.5 mm 0.020 in. Valve spring Squareness Limit 2.0 mm 0.079 in. g Free length  43.6 mm 1.717 in.
  Installed tension at 32.9 mm (1.295 in.) 186±206 N 
    (19.0 ± 21.0 kgf, 41.9 ± 46.3 lbf)
 Valve lifter Lifter diameter 30.966±30.976 mm 1.2191±1.2195 in.
  Lifter bore diameter  31.000±31.016 mm 1.2205±1.2211 in.
Oil clearanceSTD0.024±0.050 mm0.0009±0.0020 in.   Limit 0.07 mm 0.0028 in.
EM±178±
ENGINE MECHANICAL Service Specifications
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Preparation
SST (SPECIAL SERVICE TOOLS)
IllustrationPart No.Part NameNote
09268±41045Injection Measuring
Tool Set
(90268±41070)No. 4 Union
Injector
(09268±41080)No. 6 Union
Cold start Injector
(09268±52010)Injection Measuring
Attachment
Injector
09268±45012EFI Fuel Pressure
Gauge
09612±24014
Steering Gear
Housing Overhaul
Tool Set
(09617±24011)Steering Rack Wrench
Fuel pressure pulsation damper
09631±22020
Power Steering
Hose Nut 14 X 17 mm
Wrench SetFuel line flare nut
09816±30010Oil Pressure
Switch SocketKnock sensor
09842±30055Wire ªGº
EFI Inspection
Cold start Injector
09842±30070Wire ªFº
EFI Inspection
Injector
09843±18020Diagnosis Check
Wire
0990±01000
Engine Control
Computer
Check Harness ªAº
FI±10 ± PreparationEFI SYSTEM
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4. VISUALLY INSPECT SPARK PLUGSCheck the spark plug for thread damage and insulator dam-
age.
If abnormal, replace the spark plug.
Recommended spark plug: ND PK20R11
NGK BKR6EP11
5. INSPECT ELECTRODE GAP
Maximum electrode gap: 1.3 mm (0.051 in.)
If the gap is greater than maximum, replace the spark plug.
Correct electrode gap of new spark plug:1.1 mm (0.043 in.)
NOTICE: If adjusting the gap of a new spark plug, bent
only the base of the ground electrode. Do not touch the
tip. Never attempt to adjust the gap on the used plug.
6. CLEAN SPARK PLUGS If the electrode has traces of wet carbon, allow it to dry and
then clean with a spark plug cleaner.
Air pressure: Below 588 kPa (6 kgf/cm2, 85 psi)
Duration: 20 seconds or less
HINT: If there are traces of oil, remove it with gasoline before
using the spark plug cleaner.
7. REINSTALL SPARK PLUGS Using a 16 mm plug wrench, install the spark plug.
Torque: 18 N Vm (180 kgf Vcm, 13 ft Vlbf)
8. RECONNECT HIGH±TENSION CORDS TO SPARK
PLUGS
(See steps 4 to 13 on pages IG±16 to 19)
IG±8
±
IGNITION SYSTEM On±Vehicle Inspection
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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.
±
LUBRICATION SYSTEM PrecautionsLU±3
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PREPARATION
SST (SPECIAL SERVICE TOOLS)
RECOMMENDED TOOLS
EQUIPMENT
Part NameNote
Oil pressure gauge
Precision straight edgeOil pump
Torque wrench
LUBRICANT
Item
Capacity
ClassificationItemLitersUS qtslmp. qtsClassification
Engine oilAPI grade SG, Energy±Conserving II
Dry fill606353multigrade. Recommended viscosity is
Drain and refill6.06.35.3gy
as shown, with SAE 5W±30 being the
w/ Oil filter change 4.85.14.2preferred engine oil.
w/o Oil filter change4.54.85.3
g
SSM (SPECIAL SERVICE MATERIALS)
Part NamePart No.Use etc.
Seal packing or equivalent08826±00080Oil pump, Oil pan
Adhesive 1344,
Three bond 1344,08833±00080Oil pressure switch
Loctite 242 or equivalent
LU±4±
LUBRICATION SYSTEM System Circuit, Operation
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OIL PRESSURE CHECK
1. CHECK ENGINE OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If the quality is poor, replace the oil.
Oil grade: API grade SG, Energy±Conserving II multi- grade. Recommended viscosity is as shown,
with SAE 5W±30 being the preferred engine
oil.
2. CHECK ENGINE OIL LEVEL The 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 OIL PRESSURE SWITCH, AND INSTALL OIL PRESSURE GAUGE
5. WARM UP ENGINE
Allow the engine to warm up to normal operating tempera-
ture.
6. CHECK OIL PRESSURE
Oil pressure:
At idling 29 kPa (0.3 kgf/cm
2, 4.3 psi)
or more
At 3,000 rpm 294±588 kPa (3.0±6.0 kg/cm
2, 43±85 psi)
7. REMOVE OIL PRESSURE GAUGE AND REINSTALL OILPRESSURE SWITCH
Apply adhesive to two or three threads of the oil pressure
switch.
Adhesive: Part No. 08833±00080, THREE BOND 1344,
LOCTITE 242 or equivalent
8. START ENGINE AND CHECK FOR LEAKS
9. REINSTALL ENGINE UNDER COVER
±
LUBRICATION SYSTEM Oil Pressure CheckLU±5
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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.
±
LUBRICATION SYSTEM Oil PumpLU±11
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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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