2006 Lexus GS430 maintenance

MAINTENANCE
496
DOES YOUR VEHICLE NEEDREPAIRING?
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
If you notice any of these clues, take your vehicle to your Lexus
dealer as soon as possible. It probably needs adjustment or
repair.
CAUTION
Do not continue driving with the vehicle unchecked. It
could result in serious vehicle damage and possibly
personal injury.

MAINTENANCE
497
EMISSION INSPECTION AND
MAINTENANCE (I/M) PROGRAMS
Some states have vehicle emission inspection programs
which include OBD (On −Board Diagnostics) checks.
The OBD system monitors the operation of the emission
control system. When the OBD system determines that a
problem exists somewhere in the emission control system, the
malfunction indicator lamp comes on. In this case, your vehicle
may not pass the I/M test and need to be repaired. Contact
your Lexus dealer to service the vehicle.
Even if the malfunction indicator lamp does not come on, your
vehicle may not pass the I/M test as readiness codes have not
been set in the OBD system.
Readiness codes are automatically set during ordinary driving.
However, when the battery is disconnected or run down, the
codes are erased. Also, depending on your driving habits, the
codes may not be completely set.
Also, if the malfunction indicator lamp had come on recently
due to temporary malfunction such as a loose fuel tank cap,
your vehicle may not pass the I/M test.
The malfunction indicator lamp will go off after taking several
driving trips, but the error code in the OBD system will not be
cleared unless about 40 trips or more are taken.
If your vehicle does not pass the I/M test and the malfunction
indicator lamp does not come on, contact your Lexus dealer to
prepare the vehicle for re −testing.

MAINTENANCE
498

INTRODUCTION
505
After checking the items, install the engine compartment
covers and insert the plastic clips in their original
positions.
1
When inserting the plastic screw, push it in.
G61005
2When inserting the clips, do as shown above.
NOTICE
After install the engine compartment cover, make sure
the cover is securely in its original position.
DOITYOURSELF SERVICE
PRECAUTIONS
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 508.
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:

INTRODUCTION
508
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
Oil grade: API grade SL “Energy −Conserving” or ILSAC
multigrade engine oil. For recommended oil viscosity, see
page 525.
Tools:
 Rag or paper towel
 Funnel (only for adding oil)
Checking the engine coolant level
Parts (if level is low):
”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.
“Toyota Super Long Life Coolant” is a mixture of 50%
coolant and 50% deionized water (for the U.S.A.) or 55% of
coolant and 45% deionized water (for Canada).
Tools:
 Funnel (only for adding coolant)
Checking brake fluid
Parts (if level is low):
FMVSS No. 116 DOT 3 or SAE J1703 brake fluid
Tools:
 Funnel (only for adding fluid)
Checking battery condition
Tools:
Warm water
 Baking soda
 Grease
 Conventional wrench (for terminal clamp bolts)

ENGINE
518
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 standard 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 threeway 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, occasionally, you may notice light knocking for a
short
time while accelerating or driving up hills. This is normal
and there is no need for concern.
Gasoline containing detergent additives
Lexus recommends the use of gasoline that contains
detergent a dditives to avoid buildup of engine deposits.
However, all gasoline sold in the U.S. contains detergent
additives to keep clean and/or clean intake systems.
Quality gasoline
Automotive manufacturers in the U.S., Europe and Japan
have developed a specificat ion for quality fuel named
WorldWide Fuel Charter (WWFC) that is expected to be
applied world wide. The WWFC consists of four
categories that depend on required emission levels. In the
U.S., category 3 has been adopted. The WWFC improves
air quality by providing for better emissions in vehicle
fleets, and customer satisfaction through better vehicle
performance.

ENGINE
521
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.
Oil consumption: Max. 1.0 L per 1000 km (1.1 qt./600 miles,
0.9 lmp·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.
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 ”Checking the
engine oil level” on page 522.

CHASSIS
533
– AUTOMATIC TRANSMISSION
Fluid capacity Drain and refill
1.7 L (1.5 qt., 1.8 lmp.qt.)
Fluid typeToyota Genuine ATF WS*
*Change automatic transmission fluid only as necessary.
Generally, it is necessary to change automatic transmission
fluid only if your vehicle is driven under one of the Special
Operating Conditions listed in your “Owner’s Manual
Supplement / Scheduled Maintenance”. When changing the
automatic transmission fluid, use only “Toyota Genuine ATF
WS” (ATF JWS3324 or NWS9638) to aid in assuring optimum
transmission performance.NOTICE
Using automatic transmission fluid other than “Toyota
Genuine ATF WS” may cause deterioration in shift
quality, locking up of your transmission accompanied
by vibration, and ultimately damage the automatic
transmission of your vehicle.
– BRAKES
Pedal clearance *
173 mm (2.9 in.) Min.
Pedal free play1.0 − 2.0 mm (0.04 − 0.08 in.)
Brake pad wear limit1.0 mm (0.04 in.)
Parking brake lining wear limit1.0 mm (0.04 in.)
Parking brake adjustment *25 − 7 clicks
Fluid typeSAE J1703 or FMVSS No. 116 DOT 3
*1Minimum pedal clearance when depressed with the force of 196 N (20 kgf,\
44 lbf.) with the engine running
*
2Parking brake adjustment when depressed with the force of 300 N (30.6 k\
gf, 67.4 lbf.)