2006 TOYOTA 4RUNNER cooling

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Idling for a long period with the air
conditioning on in stop
−and− go traffic.
Towing a trailer.
NOTICE
Do not remove the thermostat in
the engine cooling system as this
may cause the engine to overheat.
The thermostat is designed to con-
trol the flow of coolant to keep the
temperature of the engine within
the specified operating range.
 Do not continue driving with an
overheated engine. See “If your ve-
hicle overheats” on page 378 in
Section 4.
The tachometer indicates engine speed
in thousands of rpm (revolutions per
minute). Use it while driving to select
correct shift points and to prevent en-
gine lugging and overrevving.
Driving with the engine running too fast
causes excessive engine wear and poor
fuel economy. Remember, in most cases
the slower the engine speed, the greater
the fuel economy.
NOTICE
Do not let the indicator needle get
into the red zone. This may cause
severe engine damage.
Tachometer

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“AUTO” button
For automatic operation of the air condi-
tioning, push the “AUTO” button. An indi-
cator light will illuminate to show that the
automatic operation mode has been se-
lected.
In the automatic operation mode, the air
conditioning selects the most suitable fan
speed, air flow, air intake and on −off of
the air conditioning according to the tem-
perature.
When you push the “AUTO” button with
the air intake mode at FRESH, internal
circulation may be applied for maximum
cooling.
You may use manual controls if you want
to select your own settings.
Fan speed selector
Select the mode button you desire to ad-
just the fan speed and push it. An indica-
tor light will illuminate to show which fan
speed mode is being selected.
In automatic operation, you do not have
to adjust the fan speed unless you desire
another fan speed mode. Temperature selector
To increase the temperature, push the
“UP” side, to decrease it, push the
“DOWN” side.
“LO” appears when you adjust to maxi-
mum cooling, and “HI” appears when you
adjust to maximum warming.
“OFF” button
Push the “OFF” button to turn off the air
conditioning system.
Air flow selector
Push one of the buttons to select the
vents used for air flow. An indicator light
will illuminate to show which air flow
mode is being selected.
In automatic operation, you do not have
to select the air flow unless you desire
another air flow mode.
1. Panel— Air flows from the instrument
panel vents and rear vents.
2. Bilevel— Air flows from both the floor
vents, the instrument panel vents and
rear vents.
3. Floor— Air flows mainly from the floor
vents.

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“AUTO” button
For automatic operation of the air condi-
tioning, push the “AUTO” button. An indi-
cator light will illuminate to show that the
automatic operation mode has been se-
lected.
In the automatic operation mode, the air
conditioning selects the most suitable fan
speed, air flow, air intake and on −off of
the air conditioning according to the tem-
perature.
When you push the “AUTO” button with
the air intake mode at FRESH, internal
circulation may be applied for maximum
cooling.
You may use manual controls if you want
to select your own settings.
Fan speed selector
Select the mode button you desire to ad-
just the fan speed and push it. An indica-
tor light will illuminate to show which fan
speed mode is being selected.
In automatic operation, you do not have
to adjust the fan speed unless you desire
another fan speed mode. Temperature selector
To increase the temperature, push the “
”
side, to decrease it, push the “ ” side.
“LO” appears when you adjust to maxi-
mum cooling, and “HI” appears when you
adjust to maximum warming.
“DUAL” button
This button is used to set the tempera-
tures independently for the driver ’s seat
and front passenger seat.
Pushing the button changes the mode
from independent and linked.
Independent mode: Temperatures can be
set independently for the driver ’s seat and
front passenger ’s seat. An indicator light
will illuminated to show that the indepen-
dent mode has been selected.
Linked mode: The same temperature is
set for the driver’s seat and front passen-
ger ’s seat.
When the temperature for the front pas-
senger ’s seat is changed in linked mode,
the mode is changed automatically to in-
dependent mode.
“OFF” button
Push the “OFF” button to turn off the air
conditioning system.
Air flow selector
Push one of the buttons to select the
vents used for air flow. An indicator light
will illuminate to show which air flow
mode is being selected.
In automatic operation, you do not have
to select the air flow unless you desire
another air flow mode.
1. Panel— Air flows from the instrument
panel vents and rear vents.
2. Bilevel— Air flows from both the floor
vents, the instrument panel vents and
rear vents.
3. Floor— Air flows mainly from the floor
vents.

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If following another vehicle on a dusty
road, or driving in windy and dusty
conditions, it is recommended that the
air intake selector be temporarily set to
RECIRCULATE, which will close off the
outside passage and prevent outside
air and dust from entering the vehicle
interior.
Heating
For best results, set controls as follows:
For automatic operation—
Press in the “AUTO” button.
Temperature— To the desired
temperature
Air intake—FRESH (outside air)
Air conditioning—OFF
For manual operation—
Fan speed— To the desired fan speed
Temperature— To w a r d s WARM
Air intake—FRESH (outside air)
Air flow—FLOOR
Air conditioning—OFF
For quick heating, select recirculated
air for a few minutes. To keep the
windows from fogging, select fresh af-
ter the vehicle interior has been war-
med.
Press the “A/C” button on for dehumidi-
fied heating.
Choose floor/windshield air flow to heat
the vehicle interior while defrosting or
defogging the windshield. Air conditioning
For best results, set controls as follows:
For automatic operation—
Press in the “AUTO” button.
Temperature— To the desired
temperature
Air intake—FRESH (outside air)
Air conditioning—ON
For manual operation—
Fan speed— To the desired fan speed
Temperature— To w a r d s COLD
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—ON
For quick cooling, select recirculated
air for a few minutes.

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Ventilation
For best results, set controls as follows:
For automatic operation—
Press in the “AUTO” button.
Temperature— Towards low temperature
Air intake—FRESH (outside air)
Air conditioning—OFF
For manual operation—
Fan speed— To the desired fan speed
Temperature— To w a r d s COLD
Air intake—FRESH (outside air)
Air flow—PANEL
Air conditioning—OFF
Defogging and defrosting
—The inside of the windshield
For best results, set controls as follows:
—For automatic operation
Temperature— To w a r d s high temperature
to heat; low temperature
to cool
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
—For manual operation
Fan speed— To the desired fan speed
Temperature— To w a r d s high temperature
to heat; low temperature
to cool
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
Pressing the windshield air flow button
turns on the defogging function with the
purpose of clearing the front view.
When pressing the windshield air flow but-
ton, the air intake selects FRESH auto-
matically. This is to clean up the front
view more quickly.
It is not possible to return to RECIRCU-
LATE in this mode. Press the “A/C” button for dehumidified
heating or cooling. This setting clears the
front view more quickly.
On humid days, do not blow cold air
on the windshield—the difference be-
tween the outside and inside tempera-
tures could make the fogging worse.
—The outside of the windshield
For best results, set controls as follows:
—For automatic operation
Temperature— Towards high temperature
Air intake—FRESH (outside air)
Air flow—WINDSHIELD
—For manual operation
Fan speed— To the desired fan speed
Temperature— Towards high temperature
Air intake—FRESH (outside air)
Air flow—WINDSHIELD

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Pressing the windshield air flow button
turns on the defogging function with the
purpose of clearing the front view.
When pressing the windshield air flow but-
ton, the air intake selects FRESH auto-
matically. This is to clean up the front
view more quickly.
It is not possible to return to RECIRCU-
LATE in this mode.
Press the “A/C” button for dehumidified
heating or cooling. This setting clears the
front view more quickly.
To heat the vehicle interior while de-
frosting the windshield, choose
floor/windshield air flow.Center vents
Side vents
Rear vents
If air flow control is not satisfactory, check
the instrument panel and rear vents. The
instrument panel and rear vents may be
opened or closed as shown.
Instrument panel and rear
vents

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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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To ensure excellent lubrication perfor-
mance for your engine, “Toyota Genuine
Motor Oil” is available, which has been
specifically tested and approved for all
Toyota engines.
Please contact your Toyota dealer for fur-
ther details about “Toyota Genuine Motor
Oil”. Look at the seethrough coolant reser-
voir when the engine is cold. The cool-
ant level is satisfactory if it is between
the “F” and “L” lines on the reservoir.
If the level is low, add the coolant. (For
the coolant type, see “Coolant type
selection” described below.)
The coolant level in the reservoir will vary
with engine temperature. However, if the
level is on or below the “L” line, add
coolant. Bring the level up to the “F” line.
If the coolant level drops within a short
time after replenishing, there may be a
leak in the system. Visually check the
radiator, hoses, radiator cap and drain
cock and water pump.
If you can find no leak, have your Toyota
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 en-
gine is hot.
Coolant type selection
Use of improper coolants may damage
your engine cooling system.
Only use “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. (Coolant
with long −life hybrid organic acid
technology is a combination of low
phosphates and organic acids.)
For the U.S.A.—“Toyota Super Long Life
Coolant” is a mixture of 50% coolant and
50% deionized water. This coolant pro-
vides protection down to about −35 C
( − 31 F).
For Canada—“Toyota Super Long Life
Coolant” is a mixture of 55% coolant and
45% deionized water. This coolant pro-
vides protection down to about −42 C
( − 44 F).
NOTICE
Do not use plain water alone.
Checking the engine coolant
level