lexus LS400 1994 Repair Manual Information / 1994 LS400: ENGINE

SECTION 6 – 2
191
SERVICE PROCEDURES AND
SPECIFICATIONS
Engine
Specifications192 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel195 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facts about engine oil consumption196 . . . . . . . . . . . . . . . . . . . . . . . .
Used engine oil197 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine oil level198 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level200 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing the air cleaner filter201 . . . . . . . . . . . . . . . . .

ENGINE
192
SPECIFICATIONS
− GENERAL
Model
Type
Bore and stroke
Displacement
Valve clearance (engine cold)
Intake
Exhaust
Drive belt tension
1UZ-FE
8 cylinder V type, 4 cycle, gasoline
87.5 x 82.5 mm (3.44 x 3.25 in.)
3969 cm
3 (242.1 cu.in.)
0.15 − 0.25 mm (0.006 − 0.010 in.)
0.25 − 0.35 mm (0.010 − 0.014 in.)
Automatic adjustment
− LUBRICATION SYSTEM

10W-30
5W-30 Preferred
Temperature range anticipated before next oil change
ENGINE
193 Oil capacity
Drain and refill
with filter
without filter
Oil grade
Recommended oil viscosity (SAE):
5.1 L (5.4 qt., 4.5 Imp.qt.)
4.8 L (5.1 qt., 4.2 Imp.qt.)
API grade SG or SH, Energy-Conserving II multigrade engine
oil or ILSAC multigrade engine oil
− COOLING SYSTEM
Capacity
Coolant type
10.8 L (11.4 qt., 9.5 Imp.qt.)
Ethylene-glycol coolant (Do not use alcohol type.)
− FUEL
Fuel type
Research octane umber
Only UNLEADED
96 (Octane Rating 91) or higher
− IGNITION SYSTEM

194Spark plug− Make NIPPONDENSO
NGK
− Gap
PK20R11
BKR6EP11
1.1 mm (0.043 in.)
− ELECTRICAL SYSTEM
Battery− Specific gravity reading at 20
C (68
F):
− Charging rates
1.280 Fully charged
1,180 Half charged
1.080 Discharged
Quick charge 15A max.
Slow charge 5A max.

ENGINE
195
FUEL
Fuel type
Your vehicle must use only unleaded gasoline.
To help prevent gas station mixups, your Lexus has a smaller
fuel tank opening. The special nozzle on pumps with unleaded
fuel will fit it, but the larger nozzle on pumps with leaded gas
will not.
NOTICE:
Do not use leaded gasoline. Use of leaded gasoline will
cause the three-way catalytic converter to lose its
effectiveness and the emission control system to
function improperly. Also, this can increase
maintenance costs.
Octane number
Select premium unleaded gasoline with a Research
Octane Number of 96 (Octane Rating 91) or higher for
optimum engine performance. However, if such premium
type cannot be obtained, you may temporarily use
unleaded gasoline with an octane number as low as 91.
Use of unleaded fuel with an octane number or rating lower
than stated above will cause persistent heavy knocking. If
severe, this will lead to engine damage.If your engine knocks ...
If you detect heavy knocking even when using the
recommended fuel, or if you hear steady knocking while
holding a steady speed on level roads, consult your Lexus
dealer.
However, now and then, you may notice light knocking for a
short time while accelerating or driving up hills. This is no
cause for concern.
Gasolines containing detergent additives
Lexus recommends use of gasolines that contain
detergent additives to avoid build-up of engine deposits.
For further details, ask your Lexus dealer or a local gasoline
retailer.
Gasolines containing MTBE
Gasolines that contain MTBE (Methyl Tertiary-Butyl Ether)
are available in the market. If you use a gasoline mixed
with MTBE, make certain that it does not contain more
than 15% of MTBE.
If the use of gasolines containing MTBE causes poor drivability
and / or poor fuel economy, you should discontinue the use of
fuels containing MTBE.

ENGINE
196
Gasolines containing alcohol
Gasohol is a mixture of gasoline and ethanol. If you use
gasohol in your Lexus, be sure that it is unleaded, has an
octane rating no lower than 87 and does not contain more
than 10% ethanol. Lexus does not recommend the use of
gasolines containing methanol.
If you use gasoline containing methanol, use only gasoline
meeting the requirements above and also containing less than
5% methanol with cosolvents and corrosion inhibitors for
methanol.
NOTICE:
Do not use gasohol other than stated above. It will
cause fuel system damage or vehicle performance
problems.
If drivability problems are encountered (poor hot
starting, vaporizing, engine knock, etc.), discontinue
its use.
Take care not to spill gasohol during refueling.
Gasohol may cause paint damage.
Fuel tank capacity
85 L (22.5 gal., 18.7 Imp. gal.)
FACTS ABOUT ENGINE OIL
CONSUMPTION
Functions of engine oil
Engine oil has the primary function of lubricating and cooling
the inside of the engine, and plays a major role in maintaining
the engine in proper working order.
Engine oil consumption
It is normal that an engine should consume some engine
oil during normal engine operation. The causes of oil
consumption in a normal engine are as follows.
Oil is used to lubricate pistons, piston rings and cylinders.
A thin film of oil is left on the cylinder wall when a piston
moves downwards in the cylinder. High negative pressure
generated when the vehicle is decelerating sucks some of
this oil into the combustion chamber. This oil as well as
some part of the oil film left on the cylinder wall is burned by
the high temperature combustion gases during the
combustion process.

ENGINE
197 Oil is also used to lubricate the stems of the intake valves.
Some of this oil is sucked into the combustion chamber
together with the intake air and is burned along with the fuel.
High temperature exhaust gases also burn the oil used to
lubricate the exhaust valve stems.
The amount of engine oil consumed depends on the
viscosity of the oil, the quality of the oil and the way the
vehicle is driven.
More oil is consumed under driving conditions such as high
speeds and frequent acceleration and deceleration.
A new engine consumes more oil, since its pistons, piston rings
and cylinder walls have not become conditioned.
When judging the amount of oil consumption, keep in
mind that the oil may have become diluted, making it
difficult to judge the true level accurately.
For example, if a vehicle is used for repeated short trips and
consumes a normal amount of oil, the dipstick may not show
any drop in the oil level at all, even after 1000 km (600 miles)
or more. This is because the oil is gradually becoming diluted
with fuel or moisture, making it appear that the oil level has not
changed.
The diluting ingredients evaporate out when the vehicle is then
driven at high speeds, as on an expressway, making it appear
that oil is excessively consumed after driving at high speeds.
Importance of engine oil level check
One of the most important points in proper vehicle
maintenance is to keep the engine oil at the optimum level so
that oil function will not be impaired. Therefore, it is essential
that the oil level be checked regularly. Lexus recommends that
the oil level be checked every time you refuel the vehicle.
NOTICE:
Failure to check the oil level regularly could lead to
serious engine troubles due to insufficient oil.
For detailed information on oil level check, see “Checking the
engine oil level” on page 198.
USED ENGINE OIL
CAUTION:
Used engine oil contains potentially harmful
contaminants which may cause skin disorders such as
inflammation or skin cancer, so care should be taken to
avoid prolonged and repeated contact with it. To
remove used engine oil from your skin, wash
thoroughly with soap and water.
Do not leave used oil within the reach of children.
Dispose of used oil and used oil filters only in a safe and
acceptable manner. Do not dispose of used oil and
used oil filters in household trash, in sewers or onto the
ground. Call your Lexus dealer or a service station for
information concerning recycling or disposal.

ENGINE
198
CHECKING THE ENGINE OIL
LEVEL
Low line
Add oilO.K.
Too full
Full line
With the engine at operating temperature and turned off,
check the oil level on the dipstick.
1. To get a true reading, the vehicle should be on a level spot.
After turning off the engine, wait a few minutes for the oil to
drain back into the bottom of the engine.
2. Pull out the dipstick, and wipe it clean with a rag.
3. Reinsert the dipstick and push it in as far as it will go, or the
reading will not be correct.
4. Pull the dipstick out and look at the oil level on the end. If it
is between the full line and the low line, it is O.K.
If the oil level is below or only slightly above the low line,
add engine oil of the same type as already in the engine.
Remove the oil filler cap and add engine oil in small quantities
at a time, checking the dipstick. The approximate quantity of
oil needed to fill between the low line and the full line on the
dipstick is indicated below.
When the level reaches within the correct range, return the
filler cap and turn the cap clockwise until you hear a click.
Oil quantity. L (qt., Imp. qt.) 1.5 (1.6., 1.3)
NOTICE:
Avoid overfilling, or the engine could be damaged.
Check the oil level on the dipstick once again after
adding the oil.

ENGINE
199
Engine oil selection
Use API SG or SH, Energy-Conserving II multigrade engine oil
or ILSAC multigrade engine oil. Recommended viscosity is as
follows with SAE 5W-30 being the preferred engine oil for your
vehicle.
Recommended viscosity (SAE):
Temperature range anticipated before next oil change
10W-30
5W-30 Preferred
If you use SAE 10W-30 engine oil in extremely low
temperatures, the engine may become difficult to start, so
SAE 5W-30 engine oil is recommended.
Oil identification marks
API Service SymbolILSAC Certification Mark
Either or both API registered marks are added to some oil
containers to help you select the oil you should use.
The API Service Symbol is located anywhere on the outside
of the container.
The top portion of the label shows the oil quality by API
(American Petroleum Institute) designation such as SH.
The center portion of the label shows the SAE viscosity
grade such as SAE 5W-30. “Energy-Conserving II”, shown
in the lower portion, indicates that the oil has fuel-saving
capabilities. Oils marked “Energy-Conserving II” will have
higher fuel-saving capabilities than oils marked
“Energy-Conserving”.

ENGINE
200The ILSAC (International Lubricant Standardization and
Approval Committee) Certification Mark is displayed on the
front of the container.
CHECKING THE ENGINE COOLANT
LEVEL
Reservoir cap
Upper line
Lower line
Park the vehicle at a level spot and look at the see-through
coolant reservoir when the engine is cool. The coolant
level is satisfactory if it is between the upper and lower
lines on the tank. If the level is low, add ethylene-glycol
type coolant.
The coolant level in the reservoir will vary with engine coolant
temperature. However, if the level is on or below the lower line,
add coolant to bring the level up to the upper line.Use only ethylene-glycol type coolant. It will prevent freezing
and corrosion. Neither supplemental inhibitors nor additives
are needed nor recommended. (For information on ethylene-
glycol coolant, see also “Engine coolant selection” on this
page.)
If the coolant level drops within a short time after replenishing,
there may be a leak in the system. Visually check the radiator,
hoses, reservoir cap, drain cock and water pump.
If no leak can be found, have the cap pressure tested at your
Lexus dealer.
CAUTION:
To prevent burning yourself, do not remove the reservoir
cap when the engine is hot.
Engine coolant selection
Your coolant must contain ethylene-glycol antifreeze. In
addition to preventing freezing and subsequent damage to the
engine, this will also prevent corrosion. Further supplemental
inhibitors or additives are neither needed nor recommended.
Read the antifreeze container for information on freeze
protection. Follow the manufacturer’s directions for how much
to mix with water. The total capacity of the cooling system is
given on page 193. We recommend 50% solution be used for
your Lexus, or a sufficient quantity to provide protection to
about −35
C (−31
F).
NOTICE:
Do not use alcohol type antifreeze or plain water alone.