2006 Lexus GX470 cooling

STARTING AND DRIVING
343

If the engine becomes difficult to start or stalls
frequently, take your vehicle in for a checkup as
soon as possible. Remember, your Lexus dealer
knows your vehicle and its threeway catalytic
converter system best.
 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
431
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?
 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.

61PY009
INTRODUCTION
494
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
496
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 498.
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 leave anything that may burn easily, such as
paper or rags, in the engine compartment.
 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 fan or radiator grille. With the
ignition on, the electric cooling fan will automatically
start to run if the air conditioning is on.

ENGINE
504— COOLING SYSTEM
Capacity
12.9 L (13.6 qt., 11.4 Imp. qt.)
Coolant type“Toyota Super Long Life Coolant” or similar high quality
ethylene glycol based non −silicate, non− amine, non−nitrite,
and non −borate coolant with long −life hybrid organic acid
technology (Coolant with long −life hybrid organic acid
technology is a combination of low phosphates and organic
acids.)
Do not use plain water alone.
NOTE:
“Toyota Super Long Life Coolant” is used in your Lexus vehicle at factory fil\
l. In order to avoid technical problems, only use “Toyota
Super Long Life Coolant” or similar high quality ethylene glycol based non −silicate, non −amine, non −nitrite, and non −borate coolant
with long−life hybrid organic acid technology. (Coolant with long −life hybrid organic acid technology is a combination of low
phosphates and organic acids.) Please contact your Lexus dealer for further deta\
ils.
— FUEL
Fuel type
Unleaded gasoline only
Octane rating91 (Research octane number 96) or higher

ENGINE
509
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.
Oil consumption: Max. 1.0 L per 1000 km (1.1 qt./600 miles,
0.9 Imp. qt./600 miles)
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
514
CHECKING THE ENGINE COOLANTLEVEL
1Reservoir cap2“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 the coolant. (For the coolant type, see “Coolant
type selection” described below.)
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. 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.

ENGINE
515
Coolant type selection
Use of improper coolants may damage your engine cooling
system.
Only use “Toyota Super Long Life Coolant” or similar high
quality ethylene glycol based non−silicate, non −amine,
non− nitrite, and non −borate coolant with long −life hybrid
organic acid technology. (Coolant with long −life hybrid organic
acid technology is a combination of low phosphates and
organic acids.)
For the U.S.A. — “T oyota Super Long Life Coolant” is a mixture
of 50% coolant and 50% deionized water. This coolant
provides protection down to about −35C (− 31F).
For Canada — “Toyota Super Long Life Coolant” is a mixture
of 55% coolant and 45% deionized water. This coolant
provides protection down to about −42C (− 44F).
NOTICE
Do not use plain water alone.
Lexus recommends “Toyota Super Long Life Coolant”, which
has been tested to ensure that it will not cause corrosion nor
result in malfunction of your engine coolant system with proper
usage. “Toyota Super Long Life Coolant” is formulated with
long−life hybrid organic acid technology and has been
specifically designed to avoid engine cooling system
malfunction on Lexus vehicles.
Please contact your Lexus dealer for further details.