2003 Lexus GX470 cooling

STARTING AND DRIVING
298
To ensure that the threeway catalytic converter and
the entire emission control system operate properly,
your vehicle must receive the periodic inspections
required by the Lexus Maintenance Schedule. For
scheduled maintenance information, refer to the
“Owner’s Manual Supplement / Scheduled
Maintenance”.
ENGINE EXHAUST CAUTION
CAUTION
Avoid inhaling the engine exhaust. It contains
carbon monoxide, which is a colorless and odorless
gas. It can cause unconsciousness or even death.
 Make sure the exhaust system has no holes or loose
connections. The system should be checked from
time to time. If you hit something, or notice a change
in the sound of the exhaust, have the system checked
immediately.
 Do not run the engine in a garage or enclosed area
except for the time needed to drive the vehicle in or
out. The exhaust gases cannot escape, making this
a particularly dangerous situation.
 Do not remain for a long time in a parked vehicle with
the engine running. If it is unavoidable, however, do
so only in an unconfined area and adjust the heating
or cooling system to force outside air into the vehicle.
 Keep the back door closed while driving. An open or
unsealed back door may cause exhaust gases to be
drawn into the vehicle.

IN CASE OF AN EMERGENCY
364B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning.
Check the following.

Is the cooling fan operating?
 Is the coolant in the acceptable range?
 Is the engine drive belt O.K.?
CAUTION
When the engine is running, keep hands and clothing
away from the moving fan and engine drive belt.
 Do not attempt to remove the radiator cap when the
engine and radiator are hot. Serious injury could
result from scalding hot fluid and steam blown out
under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus
dealer.
If both conditions are O.K., after the engine coolant
temperature has cooled to normal, continue driving your
vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible
by your Lexus dealer.
IF YOU HAVE A FLAT TIRE
1. Reduce your speed gradually, keeping a straight line. Move
cautiously off the road to a safe place − well away from the
traffic. A void stopping on the center divider of a highway. Park
on a level spot with firm ground.
2. Stop the engine and turn on your emergency flashers.
3. Firmly set the parking brake and put the transmission in “P”.
4. Have everyone get out of the vehicle on the side away from
traffic.
5. Read the following instructions thoroughly.
CAUTION
When jacking, be sure to observe the following to
reduce the possibility of personal injury:
 Turn off the active height control suspension by
pushing the active height control switch.
 Follow jacking instructions.
 Do not put any part of your body under a vehicle
supported by a jack. Personal injury may occur.
 Do not start or run the engine while your vehicle is
supported by the jack.
 Stop the vehicle on a level firm ground, firmly set the
parking brake and put the transmission in “P”. Block
the wheel diagonally opposite to the one being
changed if necessary.

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

ENGINE
413
COOLING SYSTEM
Capacity
12.9 L (13.6 qt., 11.4 lmp.qt.)
Coolant type“Toyota Genuine Long Life Coolant” or equivalent
With ethylene− glycol type coolant for a proper corrosion
protection of aluminum components
Do not use alcohol type antifreeze or plain water alone.
NOTE:
“Toyota Genuine Long Life Coolant” is filled in your Lexus vehicle. In\
order to avoid technical problems, we strongly recommen d
using “Toyota Genuine Long Life Coolant” or equivalent. Please contact your \
Lexus dealer for further details.
FUEL
Fuel type
Only UNLEADED
Octane rating87 (Research octane number 91) or higher
IGNITION SYSTEMSpark plug − Make
DENSO
NGK
− Gap
SK20R11
IFR6A11
1.1 mm (0.043 in.)
ELECTRICAL SYSTEM
Battery Open voltage at 20C (68F):
Charging rates
12.6 − 12.8 V Fully charged
12.2 − 12.4 V Half charged
11.8 − 12.0 V Discharged
[Voltage that is checked 20 minutes after the key is removed
with all the lights turned off]
5A max.

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.

ENGINE
422
CHECKING THE ENGINE COOLANTLEVEL
 1 Reservoir cap 2 “F” (upper) line 3 “L” (lower) line
Look at the seethrough coolant reservoir when the
engine is cold. The coolant level is satisfactory if it is
between the“F” and “L” lines on the reservoir. If the level
is low, add ethyleneglycol type coolant for a proper
corrosion protection of aluminum components.
The coolant level in the reservoir will vary with engine
temperature. However, if the level is on or below the “L” line,
add coolant. Bring the level up to the “F” line.
Always use ethylene −glycol type coolant for a proper corrosion
protection of aluminum components. See information in the
next column. If the coolant level drops within a short time after replenishing,
there
may be a leak in the system. Visually check the radiator,
hoses, engine coolant filler cap, radiator cap and drain cock
and water pump.
If you can find no leak, have your Lexus dealer test the radiator
cap pressure and check for leaks in the cooling system.
CAUTION
To prevent burning yourself, do not remove the radiator
cap when the engine is hot.
Coolant type selection
Use of improper coolants may damage your engine cooling
system. Your coolant must contain ethylene −glycol type
coolant for proper corrosion protection of your engine that
contains aluminum components. We have used “Toyota
Genuine Lo ng Life Coolant” in your Lexus vehicle. In order to
avoid technical problems, we strongly recommend using
“Toyota Genuine Long Life Coolant” or equivalent.
In addition to preventing freezing and subsequent damage to
the engine, this type of coolant will also prevent corrosion.
Further supplemental inhibitors or additives are neither
needed nor recommended.
Read the coolant container for information on freeze
protection. Follow the manufacturer’s directions for how much
to mix with plain water (preferably demineralized water or
distilled water). The total capacity of the cooling system is
given on page 413.

ENGINE
423
We recommend a 50% solution for your Lexus, to provide
protection
down to about −35C (− 31F). When it is extremely
cold, to provide protection down to about −50C (−58F), a
60% solution is recommended. Do not use more than 70%
solution for better coolant performance.
NOTICE
Do not use alcohol type antifreeze or plain water alone.
The engine cooling system is integral to maximizing
performance of your Lexus vehicle. In line with this, it is
strongly recommended that you use “Toyota Genuine Long
Life Coolant” for protecting the system, as it is an
ethylene −glycol based premium antifreeze coolant with
excellent corrosion protection properties that has been
specifically formulated for use in Lexus vehicles.
Please contact your Lexus dealer for further details about
“Toyota Genuine Long Life Coolant”.
CHECKING THE RADIATOR AND CONDENSER
If either of the above parts are extremely dirty or you are not
sure of their condition, take your vehicle to a Lexus dealer.
CAUTION
To prevent burning yourself, be careful not to touch the
radiator or condenser when the engine is hot.
NOTICE
To prevent damage to the radiator and condenser, do
not perform the work by yourself.

CHASSIS
439
Chain installation
Install the chains on the rear tires as tightly as possible.
Do not use tire chains on the front tires. Retighten chains
after driving 0.5 1.0 km (1/4 1/2 mile).
When installing chains on your tires, carefully follow the
instructions of the chain manufacturer.
CAUTION
Do not exceed 50 km/h (30 mph) or the chain
manufacturer’s recommended speed limit,
whichever is lower.
 Drive carefully avoiding bumps, holes, and sharp
turns, which may cause the vehicle to bounce.
 Avoid sharp turns or lockedwheel braking, as use of
chains may adversely affect vehicle handling.
 When driving with chains installed, be sure to drive
carefully. Slow down before entering curves to avoid
losing control of the vehicle. Otherwise an accident
may occur.
NOTICE
When jacking up or installing tire chains, be sure to turn
off the rear height control air suspension with the
“HEIGHT CONTROL OFF” switch and stop the engine.
Otherwise, the vehicle height may change because of
the automatic leveling function resulting in accident.
REPLACING WHEELS
When to replace your wheels
If you have wheel damage such as bending, cracks or
heavy corrosion, the wheel should be replaced.
If you fail to replace a damaged wheel, the tire may slip off the
wheel or cause loss of handling control.
Replacement with used wheels is not recommended as they
may have been subjected to rough treatment or high mileage
and could fail without warning. Also, bent wheels which have
been straightened may have hidden structural damage and
therefore should not be used. Never use an inner tube in a
leaking wheel which is designed for a tubeless tire.
Wheel selection
When replacing wheels, care should be taken to ensure
that they are equivalent to those removed in load capacity,
diameter, rim width, and offset.
Correct replacement wheels are available at your Lexus
dealer.
A wheel of a different size or type may adversely affect
handling, wheel and bearing life, brake cooling,
speedometer/odometer calibration, stopping ability, headlight
aim, bumper height, vehicle ground clearance, and tire or snow
chain clearance to the body and chassis.