Page 309 of 389

MAINTENANCE
296
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.
2003 IS300 from Aug. '02 Prod. (OM53439U)
Page 315 of 389

INTRODUCTION
302
DO±IT±YOURSELF 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 ºParts and toolsº on page 303.
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 the ignition is off if you work near the electric
cooling fan or radiator grille. With the ignition on, the
electric cooling fan may automatically start to run if
the air conditioning is on and/or if the coolant
temperature is high.
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.
2003 IS300 from Aug. '02 Prod. (OM53439U)
Page 332 of 389

ENGINE
319
CHECKING THE ENGINE COOLANTLEVEL
SV62006
1Reservoir cap 2Upper line 3Lower line
Look at the see±through coolant reservoir when the
engine is cold. The coolant level is satisfactory if it is
between theºFULLº and ºLº lines on the reservoir. If the
level is low, add ethylene±glycol 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 ºLº line,
add coolant. Bring the level up to the ºFULLº 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. 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 ºToyota
Genuine Long Life Coolantº in your Lexus vehicle. In order to
avoid technical problems, we strongly recommend using
ºToyota Genuine Long Life Coolantº 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 310.
2003 IS300 from Aug. '02 Prod. (OM53439U)
Page 387 of 389

3
GAS STATION INFORMATION
Fuel selection:
Select premium unleaded gasoline with an Octane Rat-
ing of 91 (Research Octane Number 96) or higher for
optimum engine performance. However, if such pre-
mium type cannot be obtained, you may temporarily use
unleaded gasoline with an Octane Rating as low as 87
(Research Octane Number 91).
Fuel tank capacity:
66 L (17.5 gal., 14.5 lmp.gal.)
Engine oil:
ºToyota Genuine Motor Oilº or equivalent
Oil grade: API grade SL ºEnergy±Conservingº or ILSAC
multigrade engine oil.
Recommend oil viscosity ± SAE 5W±30 if normal
temperatures are below 38 C (100F)
Oil capacity: L (qt., lmp.qt.)
Drain and refill with filter 5.4 (5.7, 4.8)
without filter 5.1 (5.4, 4.5)
See page 315 for detailed information.
Engine coolant:
Capacity: 7.5 L (7.9 qt., 6.6 lmp.qt.)
Coolant type ± ºToyota Genuine Long Life Coolantº or
equivalent
With ethylene±glycol type coolant for a proper corrosion
protection of aluminum components For checking the engine coolant, see page 319.
Do not use alcohol type antifreeze or plain water alone.
Automatic transmission:
Fluid type ± Toyota Genuine ATF Type T±IV
See page 324 for detailed information.
Tire information:
See page 331 through 341 for detailed information.
Tire pressure:
Tire size: 225/45ZR17, 215/45ZR17 or P205/55R16 89V
Tire pressure: cold tires
kPa (kgf/cm
2 or bar, psi)
Ti
re sizeFrontRear
225/45ZR17 ± 240 (2.4, 35)
215/45ZR17 230 (2.3, 33) 230 (2.3, 33)
P205/55R16 89V 230 (2.3, 33) 230 (2.3, 33)
For sustained high speeds above 160 km/h (100 mph), in
countries where such speeds are permitted by law, add the
tire pressure given below to the front tires and rear tires, but
never exceed the maximum cold tire pressure molded on the
tire sidewall.
225/45ZR17 70kPa (0.8 kgf/cm
2, 0.7 bar, 10 psi)
215/45ZR17 70kPa (0.8 kgf/cm2, 0.7 bar, 10 psi)
P205/55R16 89V
Sedan 70kPa (0.8 kgf/cm
2, 0.7 bar, 10 psi)
SportCross Front: 70kPa (0.8 kgf/cm2, 0.7 bar, 10 psi)
Rear: 90kPa (0.9 kgf/cm2, 0.9 bar, 15 psi)
2003 IS300 from Aug. '02 Prod. (OM53439U)