2003 Lexus ES300 cooling

IN CASE OF AN EMERGENCY
269
IF YOUR VEHICLE OVERHEATS
If your engine coolant temperature gauge indicates
overheating, if you experience a loss of power, or if you
hear a loud knocking or pinging noise, the engine has
probably overheated.
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your
emergency flashers. Put the transmission in “P” and apply the
parking brake.
A: If steam is coming from your engine:
Turn off the engine. Leave the hood closed until there is no sign
of steam or coolant. Your engine could have been seriously
damaged already. Call your Lexus dealer for assistance.
CAUTION
To help avoid personal injury, keep the hood closed until
there is no steam. Escaping steam or coolant is sign of
very high pressure.
B: 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?
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.

INTRODUCTION
297
ENGINE COMPARTMENT OVERVIEW
1 Power steering fluid
reservoir
2 Engine oil filler cap
3 Brake fluid reservoir
4 Fuse box
5 Battery
6 Fuse box
7 Radiator
8 Condenser
9 Electric cooling fans
10 Engine oil level
dipstick
11 Washer fluid tank
12 Engine coolant
reservoir

INTRODUCTION
298
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 299.
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 and other fluids may
also be hot.
 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.
 Be sure that the ignition is off if you work near the
electric cooling fans or radiator grille. With the
ignition on, the electric cooling fans will
automatically start to run if the engine coolant
temperature is high and/or the air conditioning is on.
 Use eye protection whenever you work on or under
your vehicle where you may be exposed to flying or
falling material, fluid spray, etc.

ENGINE
307
COOLING SYSTEM
Capacity
9.2 L (9.7 qt., 8.2 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.
IGNITION SYSTEM
Spark plug − Make DENSO
NGK
− Gap
SK20R11
IFR6A11
1.1 mm (0.043 in.)
ELECTRICAL SYSTEM
Battery Open voltage at 20C (68F):
Charging rates
12.7 V Fully charged
12.3 V Half charged
11.9 V Discharged
[Voltage that is checked 20 minutes after the key is removed with all the
lights turned off]
5 A max.

ENGINE
310
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 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.

ENGINE
316If the coolant level drops within a short time after replenishing,
there
may be a leak in the system. V isually 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 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 a proper corrosion protection of your engine that
contains aluminum components. We have used “Toyota
Genuine Long 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 307. We recommend to use 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), 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 of the
“Toyota Genuine Long Life Coolant” range.

CHASSIS
331
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.
CAUTION
Do not use wheels other than the manufacturer’s
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
Otherwise, an accident may occur resulting in death or
serious injuries.
ALUMINUM WHEEL PRECAUTIONS
 When installing aluminum wheels, check that the wheel
nuts are tight after driving your vehicle the first 1600 km
(1000 miles).
 If you have rotated, repaired, or changed your tires, check
that the wheel nuts are still tight after driving 1600 km (1000
miles).
 When using tire chains, be careful not to damage the
aluminum wheels.
 Use only the Lexus wheel nuts and wrench designed for
your aluminum wheels.
 When balancing your wheels, use only Lexus balance
weights or equivalent and a plastic or rubber hammer.
 As with any wheel, periodically check your aluminum
wheels for damage. If damaged, replace immediately.

ELECTRICAL COMPONENTS
337
No.FUSEAMPERECIRCUIT
1 ABS NO.47.5
Anti−lock brake system,
vehicle skid control system,
traction control system, brake
assist system
2 A/F25Multiport fuel injection
system/sequential multiport
fuel injection system
3 DOOR125
Multiplex communication
system (power door lock
system, auto −door locking
system, wireless remote
control system)
4 TEL5No circuit
5 AM230All components in “IGN” and
“IG2” fuses and starting system
6 EFI20Multiport fuel injection
system/sequential multiport
fuel injection system
7 ALTS5Charging system
8 HEAD LH
UPR10Left −hand headlight (high
beam)
No.FUSEAMPERECIRCUIT
9 ETCS10Multiport fuel injection
system/sequential multiport
fuel injection system
10 HORN10Horns
11 IGN15Starting system
12 HEAD RH
UPR10Right −hand headlight (high
beam)
13 HAZ15Emergency flashers
14 D.C.C30All components in “ECU− B”,
“RAD NO.1” and “DOME” fuses
15 IG210
Multiport fuel injection
system/sequential multiport
fuel injection system, SRS
airbag system, front seat belt
pretensioners, cruise control
system
16 ST5Starting system
17 ADJ PDL30Power adjustable pedals
18 CDS30Electric cooling fan