maintenance LEXUS SC300 1999 Owner's Manual

ENGINE
336± IGNITION SYSTEM
Spark plug ± Make DENSO NGK
± Gap
PK16TR11
BKR5EKPB11
1.1 mm (0.043 in.)
± ELECTRICAL SYSTEM
Battery ± Maintenance type battery Specific gravity reading at 20 C (68F):
Charging rates Quick charge Slow charge
± Non±maintenance battery Open voltage at 20C (68F):
Charging rates
1.260 Fully charged
1.160 Half charged
1.060 Discharged
15A max.
5A max.
12.7V Fully charged
12.3V Half charged
11.9V Discharged
[Voltage that is checked 20 minutes after the key is
removed with all the lights turned off]
5A max.

ENGINE
337
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.
At a minimum, the gasoline you use should meet the
specifications of ASTM D4814 in the U.S.A. and CGSB
3.5±M93 in Canada.
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 rating
Select premium unleaded gasoline with an Octane Rating
of 91 (Research Octane Number 96) or higher for
optimum engine performance. However, if such premium
type cannot be obtained, you may temporarily use
unleaded gasoline with an Octane Rating as low as 87
(Research Octane Number 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 r
ecommends 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.
Improved gasolines
The American Automobile Manufacturers Association
(AAMA) has developed a specification of improved
gasolines. The AAMA specification offers optimal fuel
information for better vehicle performance and better
protection of your engine.
Lexus recommends the use of gasolines that meet the AAMA
specification, if available, for improved drivability and
emission control system.

ENGINE
340The 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 by high±speed driving 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 trouble due to insufficient oil.
For detailed information on oil level check, see ºChecking the
engine oil levelº on page 342.

ELECTRICAL COMPONENTS
382
Check the battery for corroded or loose connections,
cracks, or loose hold±down clamps.
1. If the battery is corroded, wash it off with a solution of
warm water and baking soda. Coat the terminals with grease
to prevent further corrosion.
2. If the connections are loose, tighten the clamp bolts ±but
do not overtighten.
3. Tighten the hold±down clamp only enough to keep the
battery firmly in place. Overtightening may damage the
battery case.NOTICE

Make sure the engine and all accessories are turned
off before performing maintenance.

When checking the battery, remove the ground cable
first and reinstall it last.

Be careful not to cause a short circuit with tools.

Take care no solution gets into the battery when
washing it.

ELECTRICAL COMPONENTS
383
Checking battery fluid
There are 2 types of batteries: maintenance type and
non±maintenance type.
A non±maintenance battery has ºMAINTENANCE FREE
BATTERYº on its top. A maintenance type battery does not
have such indication.
Maintenance type battery
Check the fluid condition by the fluid level lines on the side
of the battery. Or if the battery has a hydrometer on its top,
you can also check the hydrometer.
Non±maintenance battery
Check the battery condition by the hydrometer on the top of
the battery.(a) Checking by the fluid level lines (Maintenance type
battery only)

ELECTRICAL COMPONENTS
385
Check the battery condition by the hydrometer color.
Maintenance type battery
BLUE ± Good condition.
WHITE ± Charging necessary. Have the battery checked by
your Lexus dealer.
RED ± Add distilled water. (See ºAdding distilled waterº on
page 386.)
Non±maintenance type battery
BLUE ± Good condition.
WHITE ± Charging necessary. Have the battery checked by
your Lexus dealer.
RED ± Have the battery checked by your Lexus dealer.NOTICE
For non±maintenance battery:
Do not refill the battery with water.

ELECTRICAL COMPONENTS
386
Adding distilled water
(Maintenance type battery only)
1. Remove the vent plugs.
2. Add distilled water to cells needing fluid.
If the side of your battery is covered, check the water level by
looking down directly above the cell as illustrated above.
3. Retighten the vent plugs securely.
NOTICE

Do not overfill the cells. Excess electrolyte could
squirt out of the battery during heavy charging,
causing corrosion or damage.

Use a cover on the battery for longer life.
BATTERY RECHARGING
PRECAUTIONS
During recharging, the battery is producing hydrogen
gas.
Therefore, before recharging:
1. Maintenance type batteries ± Remove the vent plugs.
2. If recharging with the battery installed on the vehicle, be
sure to disconnect the ground cable.
3. Make sure the power switch on the recharger is off when
connecting the charger cables to the battery and when
disconnecting them.

ELECTRICAL COMPONENTS
387
CAUTION

Always charge the battery in an unconfined area. Do not
charge the battery in a garage or closed room where there
is not sufficient ventilation.

Non±maintenance batteries: Only do a slow charge (5 A or
less). Charging at a quicker rate is dangerous. The battery
may explode causing personal injuries.
Maintenance type batteries: Be sure to remove the vent
plugs before recharging.