engine TOYOTA 4RUNNER 2006 N210 / 4.G Repair Manual

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OCTANE RATING
Select Octane Rating 87 (Research
Octane Number 91) or higher. For
improved vehicle performance, use
premium unleaded gasoline with an
Octane Rating of 91 (Research Octane
Number 96) or higher.
Use of unleaded gasoline with an octane
rating or research octane number lower
than stated above will cause persistent
heavy knocking. If it is 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
Toyota dealer.
However, occasionally, you may notice
light knocking for a short time while accel-
erating or driving up hills. This is normal
and there is no need for concern.
GASOLINE CONTAINING DETERGENT
ADDITIVES
Toyota recommends the use of gasoline
that contains detergent additives 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
specification 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 lev-
els. In the U.S., category 3 or 4 has
been adopted. The WWFC improves air
quality by providing for better emis-
sions in vehicle fleets, and customer
satisfaction through better vehicle per-
formance.
CLEANER BURNING GASOLINE
Cleaner burning gasoline, including re-
formulated gasoline that contains oxy-
genates such as ethanol or MTBE is
available in many areas.
Toyota recommends the use of cleaner
burning gasoline and appropriately blended
reformulated gasoline. These types of gas-
oline provide excellent vehicle perfor-
mance, reduce vehicle emissions, and im-
prove air quality.OXYGENATES IN GASOLINE
Toyota allows the use of oxygenate
blended gasoline where the oxygenate
content is up to 10% ethanol or 15%
MTBE. If you use gasohol in your
Toyota, be sure that it has an octane
rating no lower than 87.
Toyota does not recommend the use of
gasoline containing methanol.
GASOLINE CONTAINING MMT
Some gasoline contain an octane en-
hancing additive called MMT (Methylcy-
clopentadienyl Manganese Tricarbonyl).
Toyota does not recommend the use of
gasoline that contains MMT. If fuel con-
taining MMT is used, your emission con-
trol system may be adversely affected.
The Malfunction Indicator Lamp on the in-
strument cluster may come on. If this hap-
pens, contact your Toyota dealer for ser-
vice.
GASOLINE QUALITY
In a very few cases, you may experience
driveability problems caused by the partic-
ular gasoline that you are using. If you
continue to have unacceptable driveability,
try changing gasoline brands. If this does
not rectify your problem, then consult your
Toyota dealer.

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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

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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.
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”.
Threeway catalytic converters

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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.
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.
Engine exhaust cautions Facts about engine oil
consumption

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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 high −speed 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 Imp. 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.
For detailed information on oil level check,
see “Checking the engine oil level” on
page 420 in Section 7
−2.
Your engine is fitted with iridiumtipped
spark plugs.
NOTICE
Use only iridiumtipped spark plugs.
Do not adjust gaps for engine perfor-
mance or smooth driveability.
Iridiumtipped spark plugs
(4.7 L V8 [2UZFE] engine)

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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 power −assist 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. 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 anti −lock brake system
function is in action, you may feel the
brake pedal pulsating and hear a noise.
In this situation, to let the anti −lock
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 anti −lock 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).
Brake system

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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 anti −lock 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 anti −lock brake system is in the
self −check 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 anti −lock 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 anti −lock brake sys-
tem activation, the brake pedal may
move a little forward.
CAUTION
Do not overestimate the antilock
brake system: Although the antilock
brake system assists in providing ve-
hicle control, it is still important to
drive with all due care and maintain
a moderate speed and safe distance
from the vehicle in front of you, be-
cause there are limits to the vehicle
stability and effectiveness of steering
wheel operation even with the anti
lock brake system on.
If tire grip performance exceeds its
capability, or if hydroplaning occurs
during high speed driving in the rain,
the antilock brake system does not
provide vehicle control.
Antilock brake system is not de-
signed to shorten the stopping dis-
tance: Always drive at a moderate
speed and maintain a safe distance
from the vehicle in front of you.
Compared with vehicles without an
antilock brake system, your vehicle
may require a longer stopping dis-
tance in the following cases:
Driving on rough, gravel or snow
covered roads.
Driving with tire chains installed.
Driving over the steps such as the
joints on the road.
Driving on roads where the road
surface is pitted or has other differ-
ences in surface height.
Install all 4 tires of specified size at
appropriate pressure: The antilock
brake system detects vehicle speeds
using the speed sensors for respec-
tive wheels’ turning speeds. The use
of tires other than specified may fail
to detect the accurate turning speed
resulting in a longer stopping dis-
tance.

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CAUTION
If the “ABS” warning light remains on
together with the brake system warn-
ing light, immediately stop your ve-
hicle at a safe place and contact your
Toyota dealer.
In this case, not only the antilock
brake system will fail but also the
vehicle will become extremely unsta-
ble during braking.
Either of the following conditions may
occur, but do not indicate a malfunc-
tion:
The light may stay on for about 60
seconds after the ignition key is turned
to the “ON” position. It is normal if it
turns off after a while.
Depressing the brake pedal repeatedly
may turn on the light. It is normal if it
turns off after a few seconds.
DRUMINDISC TYPE PARKING BRAKE
SYSTEM
Your vehicle has a drum −in −disc type
parking brake system. This type of brake
system n eeds bedding −down of the brake
shoes periodically or whenever the parking
brake shoes and/or drums are replaced. Have your Toyota dealer perform the bed-
ding−
down.
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 147 in Sec-
tion 1 −6.
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.
Brake pad wear limit
indicators

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Your Toyota is equipped with a limited −slip
center differential (transfer). If one wheel
begins to spin, the limited −slip 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.The vehicle identification number (VIN) is
also on the Certification Label.
Limitedslip differential
(fourwheel drive models) Your Toyota’s identification—
—Vehicle identification number

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4.0 L V6 (1GRFE) engine
4.7 L V8 (2UZFE) engine
The engine number is stamped on the
engine block as shown. Your new vehicle carries theft preven-
tion labels which are approximately 47
mm (1.85 in.) by 12 mm (0.47 in.).
The purpose of these labels is to reduce
the incidence of vehicle thefts by facilitat-
ing the tracing and recovery of parts from
stolen vehicles. The label is designed so
that once it is applied to a surface, any
attempt to remove it will result in destroy-
ing the integrity of the label. Transferring
these labels intact from one part to anoth-
er, will be impossible.
NOTICE
You should not attempt to remove the
theft prevention labels as it may vio-
late certain state or federal laws.
—Engine number
Theft prevention labels
(except for Canada)