2003 Lexus GX470 Oil

MAINTENANCE
397
Tire rotation
Rotate the
tires according to the maintenance schedule. (For
scheduled maintenance information, please refer to the
“Owner’s Manual Supplement / Scheduled Maintenance”.)
See page 434 for additional information.
Fluid leaks
Check underneath for leaking fuel, oil, water or other fluid after
the vehicle has been parked for a while. If you smell fuel fumes
or notice any leak, have the cause found and corrected
immediately.
Doors and engine hood
Check that all side doors and back door, operate smoothly and
all latches lock securely. Make sure the engine hood
secondary latch secures the hood when the primary latch is
released.
Vehicle interior
Items listed below should be checked regularly, e.g. while
performing periodic services, cleaning the vehicle, etc.
Lights
Make sure the headlights, stop lights, tail lights, turn signal
lights, and other lights are working. Check headlight aim.
Service reminder indicators and warning buzzers
Check that all service reminder indicators and warning buzzers
function properly. Steering wheel
Check that it has the
specified free play. Be alert for changes
in steering condition, such as hard steering, excessive free
play or strange noise.
Seats
Check that all front seat controls such as seat adjusters,
seatback recliner, etc. operate smoothly. Check that the head
restraints move up and down smoothly and that the locks hold
securely in any latched position. For folding −up second and
third seats, and detachable third seat, check that the latches
lock securely.
Seat belts
Check that the seat belt system such as buckles, retractors
and anchors operate properly and smoothly. Make sure the
belt webbing is not cut, frayed, worn or damaged.
Accelerator pedal
Check the pedal for smooth operation and uneven pedal ef fort
or catching.
Brake pedal
Check the pedal for smooth operation and the proper
clearance and free play. Check the brake booster function.
Brakes
At a safe place, check that the brakes do not pull to one side
when applied.

MAINTENANCE
399
Brake fluid level
Make sure the brake fluid level is correct. See page 430 for
additional information.
Engine oil level
Check the level on the dipstick with the engine turned off and
the vehicle parked on a level spot. See page 419 for
additional
information.
Power steering fluid level
Check the level through the reservoir. The level should be in
the “HOT” or “COLD” range depending on the fluid
temperature. See page 431 for additional information.
Exhaust system
If you notice any change in the sound of the exhaust or smell
exhaust fumes, have the cause located and corrected
immediately. (See “Engine exhaust caution” on page 298.)
DOES YOUR VEHICLE NEED REPAIRING?
Be on the alert for changes in performance and sounds, and
visual tip −offs that indicate service is needed. Some important
clues are:
 Engine missing, stumbling, or pinging
 Appreciable loss of power
 Strange engine noises
 A fluid leak under the vehicle (However, water dripping from
the air conditioning after use is normal.)
 Change in exhaust sound (This may indicate a dangerous
carbon monoxide leak. Drive with the windows open and
have the exhaust system checked immediately.)
 Flat−looking tires, excessive tire squeal when cornering,
uneven tire wear
 Vehicle pulls to one side when driving straight on a level
road
 Strange noises related to suspension movement
 Loss of brake effectiveness, spongy feeling brake pedal,
pedal almost touches floors, vehicle pulls to one side when
braking
 Engine coolant temperature continually higher than normal

61PY004
INTRODUCTION
404
ENGINE COMPARTMENT OVERVIEW
1Engine oil level
dipstick
2Engine oil filler cap
3Brake fluid reservoir
4Fuse box
5Battery
6Condenser
7Electric cooling fan
8Radiator
9Engine coolant
reservoir
10Washer fluid tank
11Power steering fluid
reservoir

INTRODUCTION
406
DOITYOURSELF 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 “Parts and tools” on page 407.
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.)
 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, other fluids and spark
plugs may also be hot.
 If the engine is hot, do not remove the radiator cap or
loosen the drain plugs to prevent burning yourself.
 Do not smoke, cause sparks or allow open flames
around fuel or the battery. Their fumes are
flammable.
 Do not get under your vehicle with just the body jack
supporting it. Always 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.
 Be extremely cautious when working on the battery.
It contains poisonous and corrosive sulfuric acid.
 Warning: Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.

INTRODUCTION
407
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 and
power steering fluid, or the transmission and power
steering 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):
“Toyota Genuine Motor Oil” or equivalent
See page 420 for details about engine oil selection.
Tools:
 Rag or paper towel
 Funnel (only for adding oil)
Checking the engine coolant level
Parts (if level is low):
“Toyota Genuine Long Life Coolant” or equivalent
See “Checking the engine coolant level” on page 422 for
instructions.
 Demineralized or distilled water
Tools:
 Funnel (only for adding coolant)

SECTION 6 – 2
410
SERVICE PROCEDURES AND
SPECIFICATIONS
Engine
Specifications411
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . .
Fuel 414
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . . . . . . .
Fuel pump shut off system 416
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facts about engine oil consumption 417
. . . . . . . . . . . . . . . . . . . . . . . .
Used engine oil 418
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . .
Checking the engine oil level 419
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level 422
. . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the radiator and condenser 423
. . . . . . . . . . . . . . . . . . . . . . .
Spark plugs 424
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .\
. . . . . . . .

62Z002
Outside temperature
ENGINE
412 LUBRICATION SYSTEM
Oil capacity Drain and refillwith filter
without filter
6.2 L (6.5 qt., 5.5 lmp.qt.)
5.7 L (6.0 qt., 5.0 lmp.qt.)
Oil gradeAPI grade SL “Energy− Conserving” or ILSAC multigrade engine oil
Recommended oil viscosity (SAE):
NOTE:
“Toyota Genuine Motor Oil” is filled in your Lexus vehicle. Use Lexus approv\
ed “Toyota Genuine Motor Oil” or equivalent to sat isfy
the above grade and viscosity. Please contact your Lexus dealer for further details.

ENGINE
417
FACTS ABOUT ENGINE OILCONSUMPTION
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.
 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 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.