1999 LEXUS SC300 maintenance

INTRODUCTION
324
DO±IT±YOURSELF SERVICEPRECAUTIONS
If you perform maintenance yourself, be sure to follow the
correct procedure given in this Section.
You should be aware that improper or incomplete servicing
may result in operating problems.
Performing do±it±yourself maintenance during the warranty
period may affect your warranty coverage. Read the separate
Lexus Warranty statement for details and suggestions.
This Section gives instructions only for those items that are
relatively easy for an owner to perform. As explained in
Section 5, there are still a number of items that must be
performed by a qualified technician with special tools.
For information on tools and parts for do±it±yourself
maintenance, see ºParts and toolsº.
Utmost care should be taken when working on your vehicle
to prevent accidental injury. Here are a few precautions that
you should be especially careful to observe:
CAUTION

When the engine is running, keep hands, clothing, and tools
away from the moving fan and engine drive belt.
(Removing rings, watches, and ties is advisable.)

INTRODUCTION
325

Right after driving, the engine compartment ± the
engine, radiator, exhaust manifold and power
steering fluid reservoir, etc. ± will be hot. So be
careful not to touch them. Oil and other fluids may
also be hot.

Do not smoke, cause sparks or allow open flames
near fuel or the battery. Their fumes are fl ammable.

Be extremely cautious when working on the battery.
It contains poisonous and corrosive sulfuric acid.

Do not get under your vehicle with just the body jack
supporting it. Al ways use automotive jack stands or
other solid supports.

Use eye protection whenever you work on or under
your vehicle where you may be exposed to flying or
falling material, fluid spray, etc.
NOTICE

Remember that battery and ignition cables carry high
currents or voltages. Be careful of accidentally
causing a short circuit.

Before closing the engine hood, check to see that you
have not forgotten any tools, rags, etc.

Do not drive with the air cleaner removed, or excessive
engine wear could result. Also backfiring could cause
a fire in the engine compartment.

Do not overfill automatic transmission fluid, or the
transmission could be damaged.

Be careful not to scratch the glass surface with the
wiper frame.
PARTS AND TOOLS
Here is a list of parts and tools you will need to perform
do±it±yourself maintenance. Remember all Lexus parts are
designed in metric sizes, so your tools must be metric.
Checking the engine oil level
Parts (if level is low):

Use API grade SJ, ºEnergy±Conservingº multigrade
engine oil or ILSAC multigrade engine oil. For
recommended oil viscosity, see page 346.
Tools:

INTRODUCTION
327
Checking battery condition
Non±maintenance batteries
Tools:

Warm water

Baking soda

Grease

Conventional wrench (for terminal clamp bolts)
Maintenance type batteries
Parts (if level is low):

Distilled water
Tools:

Warm water

Baking soda

Grease

Conventional wrench (for terminal clamp bolts)

Coin (for vent plugs)

Funnel (only for adding distilled water)
Checking and replacing the blade type fuses
Parts (if replacement is necessary):

Fuse with same amperage rating as original
Checking the cartridge type fuses
Parts (if replacement is necessary):

Genuine Lexus fuse or equivalent with same amperage
rating as original
Adding washer fluid
Parts:

Water

Washer fluid containing antifreeze (for winter use)
Tools:

Funnel

ENGINE
333
± 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
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.