engine TOYOTA 4RUNNER 2003 N210 / 4.G Repair Manual

’03 4Runner_U (L/O 0305)
245
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
NOTICE
Do not use gasohol other than
stated above. It will cause fuel sys-
tem damage or vehicle performance
problems.
 If driveab ility problems occur (poor
hot starting, vaporizing, engine
knock, etc.), discontinue the use.
 Take care not to spill gasohol dur-
ing refueling. Gasohol may cause
paint damage.
FUEL TANK CAPACITY
87 L (23.0 gal., 19.1 Imp. gal.) The fuel pump shut off system stops sup-
plying 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 “ACC” or “LOCK” 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.
If you plan to drive your Toyota in
another country...
First,
comply with the vehicle registration
laws.
Second, confirm the availability of the cor-
rect fuel (unleaded and minimum octane
number).
Fuel pump shut off system Operation in foreign countries

’03 4Runner_U (L/O 0305)
246
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
1GRFE engine
2UZFE engine
The threeway catalytic converter is an
emission control device installed in the
exhaust system.
The purpose is to reduce pollutants in the
exhaust gas.
CAUTION
Keep people and combustible mate-
rials away from the exhaust pipe
while the engine is running. The
exhaust gas is very hot.
Do not idle or park your vehicle
over anything that might burn easi-
ly such as grass, leaves, paper or
rags.
NOTICE
A large amount of unburned gases
flowing into the threeway catalytic
converter may cause it to overheat
and create a fire hazard. To prevent
this and other damage, observe the
following precautions:
Use only unleaded gasoline.
 Do not drive with an extremely low
fuel level; running out of fuel could
cause the engine to misfire, creat-
ing an excessive load on the three
way catalytic converter.
 Do not allow the engine to run at
idle speed for more than 20 min-
utes.
 Avoid racing the engine.
 Do not pushstart or pullstart your
vehicle.
 Do not turn off the ignition while
the vehicle is moving.
Threeway catalytic converters

’03 4Runner_U (L/O 0305)
247
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
Keep your engine in good running
order. Malfunctions in the engine
electrical system, electronic ignition
system/distributor ignition system
or fuel systems could cause an ex-
tremely high threeway catalytic
converter temperature.
 If the engine becomes difficult to
start or stalls frequently, take your
vehicle in for a checkup as soon
as possible. Remember, your Toyota
dealer knows your vehicle and its
threeway catalytic converter sys-
tem best.
 To ensure that the threeway cata-
lytic converter and the entire emis-
sion control system operate proper-
ly, your vehicle must receive the
periodic inspections required by the
Toyota Maintenance Schedule. For
scheduled maintenance information,
refer to the “Scheduled Maintenance
Guide” or “Owner ’s Manual Supple-
ment”.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 run-
ning. 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 and back win-
dow closed while driving. An open
or unsealed back door and back
window, may cause exhaust gases
to be drawn into the vehicle.
To allow proper operation of your
vehicle’s ventilation system, keep
the inlet grilles in front of the wind-
shield clear of snow, leaves, or oth-
er obstructions.
If you smell exhaust fumes in the
vehicle, drive with the windows
open and the back door and back
window closed. Have the cause im-
mediately located and corrected.
Engine exhaust cautions

’03 4Runner_U (L/O 0305)
248
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of
lubricating and cooling the inside of the
engine, and plays a major role in main-
taining the engine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume 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 pis-
ton 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 tem-
perature exhaust gases also burn the
oil used to lubricate the exhaust valve
stems.
The amount of engine oil consumed de-
pends on the viscosity of the oil, the
quality of the oil and the conditions the
vehicle is driven under.
More oil is consumed by highspeed driv-
ing and frequent acceleration and decel-
eration.
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 con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accurately. As an example, if a vehicle is used for
repeated short trips, and consumes a nor-
mal 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 prop-
er vehicle maintenance is to keep the en-
gine oil at the optimum level so that oil
function will not be impaired. Therefore, it
is essential that the oil level be checked
regularly. Toyota 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.
Facts about engine oil
consumption

’03 4Runner_U (L/O 0305)
249
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
For detailed information on oil level check,
see “Checking the engine oil level” on
page 324 in Section 72.
Your engine is fitted with iridiumtipped
spark plugs.
NOTICE
Use only iridiumtipped spark plugs
and do not adjust gaps for your en-
gine performance and smooth drive-
ability.
This brake system has 2 independent hy-
draulic circuits. If either circuit should fail,
the other will still work. However, the ped-
al will be harder to press, and your stop-
ping distance will increase. Also, the
brake system warning light may come on.
CAUTION
Do not drive your vehicle with only a
single brake system. Have your
brakes fixed immediately.
BRAKE BOOSTER
The brake booster uses brake fluid pres-
surized by the pump to powerassist the
brakes. If the brake booster fails during
driving, the brake system warning light
comes on and buzzer sounds continuous-
ly. In this case, the brakes may not work
properly. If they do not work well, depress
the brake pedal firmly. If the brake system
warning light comes on, immediately stop
your vehicle and contact your Toyota deal-
er.
It is not a malfunction that the brake sys-
tem warning light may stay on for 60 sec-
onds after the ignition key is turned to the
“ON” position.
Iridiumtipped spark plugs
(2UZFE engine) Brake system

’03 4Runner_U (L/O 0305)
250
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
Depressing the brake pedal repeatedly
may turn on the brake system warning
light and buzzer. It is normal if the light
turns off and the buzzer stops sounding
after a few seconds.
You may hear a small sound in the engine
compartment after the engine is started or
the brake pedal is depressed repeatedly.
This is a pump pulsating sound of the
brake system, and it is not a malfunction.
CAUTION
Do not pump the brake pedal if the
engine stalls. Each push on the
pedal uses up your brake fluid
pressure reserve.
Even if the power assist is com-
pletely lost, the brakes will still
work. But you will have to push the
pedal hard, much harder than nor-
mal. And your braking distance will
increase.
ANTILOCK BRAKE SYSTEM
(with “ABS” warning light)
The antilock brake system is designed
to help prevent lockup of the wheels
during a sudden braking or braking on
slippery road surfaces. This assists in
providing directional stability and steer-
ing performance of the vehicle under
these circumstances.
Effective way to press the ABS brake
pedal: When the antilock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the antilock
brake system work for you, just hold the
brake pedal down more firmly. Do not
pump the brake in a panic stop. This
will result in reduced braking performan-
ce.
The antilock brake system becomes op-
erative after the vehicle has accelerated
to a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerates to a speed below
approximately 5 km/h (3 mph). Depressing the brake pedal on slippery
road surfaces such as on a manhole cov-
er, a steel plate at a construction site,
joints in a bridge, etc. on a rainy day
tends to activate the antilock brake sys-
tem.
You may hear a click or motor sound in
the engine compartment for a few seconds
when the engine is started or just after
the vehicle begins to move. This means
that the antilock brake system is in the
selfcheck mode, and does not indicate a
malfunction.
When the antilock brake system is ac-
tivated, the following conditions may
occur. They do not indicate a malfunc-
tion of the system:
You may hear the antilock brake sys-
tem operating and feel the brake pedal
pulsating and the vibrations of the ve-
hicle body and steering wheel. You
may also hear the motor sound in the
engine compartment even after the ve-
hicle is stopped.
At the end of the antilock brake sys-
tem activation, the brake pedal may
move a little forward.

’03 4Runner_U (L/O 0305)
253
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
Have your Toyota dealer perform the bed-
dingdown.
BRAKE ASSIST SYSTEM
When you slam the brakes on, the
brake assist system judges as an emer-
gency stop and provides more powerful
braking for a driver who cannot hold
down the brake pedal firmly.
When you slam the brakes on, more pow-
erful braking will be applied. At this time,
you may hear a sound in the engine
compartment and feel the vibrations of the
brake pedal. This does not indicate a mal-
function.
The brake assist system becomes opera-
tive after the vehicle has accelerated to
a speed in excess of approximately 10
km/h (6 mph). It stops operating when the
vehicle decelerates to a speed below
approximately 5 km/h (3 mph).
For an explanation of this system’s warn-
ing light, see “Service reminder indicators
and warning buzzers” on page 117 in Sec-
tion 15.
The brake pad wear limit indicators on
your disc brakes give a warning noise
when the brake pads are worn to where
replacement is required.
If you hear a squealing or scraping noise
while driving, have the brake pads
checked and replaced by your Toyota
dealer as soon as possible. Expensive ro-
tor damage can result if the pads are not
replaced when necessary. When stowing luggage or cargo in the
vehicle, observe the following:
Put luggage or cargo in the luggage
compartment when at all possible. Be
sure all items are secured in place.
Be careful to keep the vehicle bal-
anced. Locating the weight as far for-
ward as possible helps maintain bal-
ance.
For better fuel economy, do not carry
unneeded weight.
CAUTION
To prevent luggage or packages
from sliding forward during braking,
do not stack anything in the lug-
gage compartment higher than the
seatbacks. Keep luggage or pack-
ages low, as close to the floor as
possible.
Do not exceed 66 kg (145 lb.) of
cargo load in the luggage compart-
ment.
Do not place anything on the flat-
tened seat or it may slide forward
during braking.
Brake pad wear limit
indicators
Luggage stowage pr
ecautions

’03 4Runner_U (L/O 0305)
254
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
Never allow anyone to ride in the
luggage compartment. It is not de-
signed for passengers. They should
ride in their seats with their seat
belts properly fastened. Otherwise,
they are much more likely to suffer
serious bodily injury, in the event
of sudden braking or a collision.
Do not place anything on the lug-
gage cover. Such items may be
thrown about and possibly injure
people in the vehicle during sudden
braking or an accident. Secure all
items in a safe place.
Do not drive with objects left on
top of the instrument panel. They
may interfere with the driver’s field
of view. Or they may move during
sharp vehicle acceleration or turn-
ing, and impair the driver’s control
of the vehicle. In an accident they
may injure the vehicle occupants.
NOTICE
Do not load the vehicle beyond the
cargo load specified on page 352 in
Section 8.
Your Toyota is equipped with a limitedslip
center differential (transfer). If one wheel
begins to spin, the limitedslip center dif-
ferential (transfer) is designed to aid trac-
tion by automatically transmitting driving
force to the wheels on the other drive
axle. It transmits driving force to the front
wheels if a rear wheel spins, and to the
rear wheels if a front wheel spins.
CAUTION
Do not start or run the engine while
your vehicle is supported by a jack.
The vehicle could be driven off the
jack and could pose a danger or re-
sult in serious injury.
NOTICE
Use only a spare tire of the same
brand, size, construction and load ca-
pacity as the original tires on your
Toyota because damage to the limit-
edslip differential could possibly oc-
cur with another tire type.
The vehicle identification number (VIN)
is the legal identifier for your vehicle.
This number is on the left top of the
instrument panel, and can be seen
through the windshield from outside.
This is the primary identification number
for your Toyota. It is used in registering
the ownership of your vehicle.
Limitedslip differential
(fourwheel drive models) Your Toyota’s identification—
—Vehicle identification number

’03 4Runner_U (L/O 0305)
255
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
The vehicle identification number (VIN) is
also on the Certification Label.1GRFE engine
2UZFE engine
The engine number is stamped on the
engine block as shown.
—Engine number

’03 4Runner_U (L/O 0305)
259
2003 4RUNNER from Apr. ’03 Prod. (OM 35820U)
STARTING AND DRIVING
Starting and driving
Before starting the engine 260
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to start the engine 260
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. .
Tips for driving in various conditions 261
. . . . . . . . . . . . . . . . . . . . . . . . . .
Offroad driving precautions 263
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winter driving tips 264
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . .
Dinghy towing 265
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . .
Trailer towing 266
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . .
How to save fuel and make your vehicle last longer 275
. . . . . . . . . . . . .
SECTION 3