2003 Lexus IS300 valve

DRIVING TIPS
264

Keep your vehicle tuned±up and in top shape. A dirty air
cleaner, improper valve clearance, dirty plugs, dirty oil and
grease, brakes not adjusted, etc. all lower engine
performance and contribute to poor fuel economy. For
longer life of all parts and lower operating costs, keep all
maintenance work on schedule, and if you often drive under
severe conditions, see that your vehicle receives more
frequent maintenance. (For scheduled maintenance
information, please refer to the ºOwner's Manual
Supplement / Scheduled Maintenanceº.)
CAUTION
Never turn off the engine to coast down hills. Your
power steering and brake booster will not function
without the engine running. Also, the emission control
system operates properly only when the engine is
running.
2003 IS300 from Aug. '02 Prod. (OM53439U)

IN CASE OF AN EMERGENCY
282
SL41002
10. Reinstall the wheel ornament.
Put the wheel ornament into position and then tap it firmly with
the side or heel of your hand to snap it into place.
CAUTION
Take due care in handling the ornament to avoid
unexpected personal injury.
11. After changing the wheel, check the air pressure of the
replaced tire. Stow all the tools, jack and flat tire securely.
If the pressure of the replaced tire is low, drive slowly to the
nearest service station and fill to the correct pressure.
Do not forget to reinstall the tire valve cap as dirt and moisture
could get into the valve core and possibly cause air leakage.
If the cap is missing, put a new one on as soon as possible.
This is the same procedure for changing or rotating your tires.
CAUTION
 When reinstalling a standard tire, take due care in
handling the ornament to avoid unexpected personal
injury.
 Before driving, make sure all the tools, jack and flat
tire are securely in place in their storage location to
reduce the possibility of personal injury during a
collision or sudden braking.
2003 IS300 from Aug. '02 Prod. (OM53439U)

ENGINE
308
SPECIFICATIONS
± GENERALModel
2JZ±GE
Type6 cylinder in line, 4 cycle, gasoline
Bore and stroke86.0 X 86.0 mm (3.39 X 3.39 in.)
Displacement2997 cm3 (182.9 cu.in.)
Valve clearance (engine cold) Intake
Exhaust0.15 ± 0.25 mm (0.006 ± 0.010 in.)
0.25 ± 0.35 mm (0.010 ± 0.014 in.)
Drive belt tensionAutomatic adjustment
2003 IS300 from Aug. '02 Prod. (OM53439U)

ENGINE
313
FUEL PUMP SHUT OFF SYSTEM
The fuel pump shut off system stops supplying fuel to the
engine to minimize the risk of fuel leakage when the engine
stalls or an airbag inflates upon collision. To restart the engine
after the fuel pump shut off system activates, turn the ignition
switch to ºACCº or ºLOCKº once and start it.
CAUTION
Inspect the ground under the vehicle before restarting
the engine. If you find that liquid has leaked onto the
ground, it is the fuel system has been damaged and it is
in need of repair. In this case, do not restart the engine.
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.
2003 IS300 from Aug. '02 Prod. (OM53439U)

CHASSIS
332
CAUTION
Keep your tire pressure at the proper level. Otherwise,
the following conditions may occur and cause an
accident.
Low tire pressure (underinflation)Ð
Excessive wear
 Uneven wear
 Poor handling
 Possibility of blowouts from overheated tire
 Poor sealing of the tire bead
 Wheel deformation and/or tire separation
High tire pressure (overinflation)Ð
 Poor handling
 Excessive wear at the center of the tire tread
 A greater possibility of tire damage from road
hazards
The following instructions for checking tire pressure should be
observed:
The pressure should be checked only when the tires are
cold. If your vehicle has been parked for at least 3 hours
and has not been driven for more than 1.5 km or 1 mile
since, you will get an accurate cold tire pressure reading.
 Always use a tire pressure gauge. The appearance of the
tire can be misleading. Besides, tire pressures that are
even just a few pounds off can degrade ride and handling.
 Do not bleed or reduce tire pressure after driving. It is
normal for the tire pressure to be higher after driving.
 Never exceed the vehicle capacity weight. The
passengers and luggage weight should be located so that
the vehicle is balanced.
 Be sure to reinstall the tire valve caps. Without the valve
caps, dirt or moisture could get into the valve core and
cause air leakage. If the caps have been lost, have new
ones put on as soon as possible.
2003 IS300 from Aug. '02 Prod. (OM53439U)

2.
Maintenance procedures for the engine, chassis,
body, electrical system, and more, are clearly
explained and illustrated.
Periodic maintenance and tune±up
Periodic maintenance and tune±up helps to prevent small
problems from growing into larger ones later on. The repair
manual outlines exactly what maintenance is required and
clearly explains how to do the work yourself step±by±step.
Areas covered include such things as spark plug replacement,
valve clearance adjustment and engine oil and filter
replacement.
Where to obtain theRepair Manual
The repair manual for IS300 written in English, may be
purchased as applicable from any Lexus dealer.
Pub. Name: 2003 IS300 Repair Manual
Pub. No.: Vol.1 RM980U1 Vol.2 RM980U2
2003 IS300 from Aug. '02 Prod. (OM53439U)