2004 TOYOTA SIENNA radiator

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If your engine coolant temperature
gauge indicates overheating, if you ex-
perience a loss of power, or if you hear
a loud knocking or pinging noise, the
engine has probably overheated. You
should follow this procedure...1. Pull safely off the road, stop the ve- hicle and turn on your emergency
flashers. Put the transmission in “P”
and apply the parking brake. Turn off
the air conditioning if it is being used.
2. If coolant or steam is boiling out of the radiator or reservoir, stop the engine.
Wait until the steam subsides before
opening the hood. If there is no coolant
boiling over or steam, leave the engine
running and make sure the electric
cooling fan is operating. If it is not,
turn the ignition off.
CAUTION
To help avoid personal injury, keep
the hood closed until there is no
steam. Escaping steam or coolant is
a sign of very high pressure.
3. Look for obvious coolant leaks from theradiator, hoses, and under the vehicle.
However, note that water draining from
the air conditioning is normal if it has
been used.
CAUTION
When the engine is running, keep
hands and clothing away from the
moving fan and engine drive belts.
4. If the coolant is leaking, stop the en-gine immediately. Call a Toyota dealer
for assistance.
5. If there are no obvious leaks, check the coolant reservoir. If it is dry, add
coolant to the reservoir while the en-
gine is running. Fill it about half full.
CAUTION
Do not attempt to remove the radiator
cap when the engine and radiator are
hot. Serious injury could result from
scalding hot fluid and steam blown
out under pressure.
6. After the engine coolant temperaturehas cooled to normal, again check the
coolant level in the reservoir. If neces-
sary, bring it up to half full again. Seri-
ous coolant loss indicates a leak in the
system. You s hould have it checked as
soon as possible at your Toyota dealer.
If your vehicle overheats

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If you are a skilled do−it−yourself mechan-
ic, the Toyota service manuals are recom-
mended. Please be aware that do −it−your-
self maintenance can affect your warranty
coverage. See “Owner ’s Warranty Informa-
tion Booklet” or “Owner ’s Manual Supple-
ment” for the details. Listed below are the general maintenance
items that should be performed as fre-
quently as specified. In addition to check-
ing the items listed, if you notice any
unusual noise, smell or vibration, you
should investigate the cause or take your
vehicle to your Toyota dealer or a quali-
fied service shop immediately. It is recom-
mended that any problem you notice be
brought to the attention of your dealer or
the qualified service shop for their advice.
CAUTION
Make these checks only with ade-
quate ventilation if you run the en-
gine.
IN THE ENGINE COMPARTMENT
Items listed below should be checked
from time to time, e.g. each time when
refueling.
Washer fluid
Make sure there is sufficient fluid in the
tank. See page 479 in Section 7
−3 for
additional information. Engine coolant level
Make sure the coolant level is between
the “FULL” and “LOW” lines on the see
−
through reservoir when the engine is cold.
See page 458 in Section 7 −2 for addition-
al information.
Radiator, condenser and hoses
Check that the front of the radiator and
condenser are clean and not blocked with
leaves, dirt, or insects. See page 460 in
Section 7 −2 for additional information.
Battery electrolyte level
Your Toyota has a maintenance free bat-
tery. You do not have to add distilled wa-
ter. For longer life of the battery, however,
see page 476 in Section 7 −3 for additional
information.
Brake fluid level
Make sure the brake fluid level is correct.
See page 462 in Section 7 −2 for addition-
al information.
Engine oil level
Check the level on the dipstick with the
engine turned off and the vehicle parked
on a level spot. See page 456 in Section
7 −2 for additional information.
General maintenance

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1. Power steering fluid reservoir
2. Windshield and rear window washerfluid tank
3. Engine oil level dipstick
4. Engine coolant reservoir
5. Engine oil filler cap
6. Brake fluid reservoir
7. Fuse block
8. Battery
9. Electric cooling fans
10. Condenser
11. Radiator
Engine compartment overview

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If you perform maintenance by yourself,
be sure to follow the correct procedure
given in this Section.
You should be aware that improper or in-
complete servicing may result in operating
problems.
Performing do−it−yourself maintenance
during the warranty period may affect your
warranty coverage. Read the separate
Toyota 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
6, there are still a number of items that
must be done by a qualified technician
with special tools.
For information on tools and Sections for
do− it−yourself maintenance, see “Parts
and tools” on page 453 in this Section.
Utmost care should be taken when work-
ing on your vehicle to prevent accidental
injury. Here are a few precautions that
you should be especially careful to ob-
serve:CAUTION
When the engine is running, keep
hands, clothing, and tools away
from the moving fan and engine
drive belts. (Removing rings,
watches, and ties is advisable.)
Right after driving, the engine
compartment—the engine, radiator,
exhaust manifold and spark plug
boots, etc.—will be hot. So be care-
ful not to touch them. Oil, fluids
and spark plugs may also be hot.
If the engine is hot, do not remove
the radiator cap or loosen the drain
plugs to prevent burning yourself.
Do not leave anything that may
burn easily, such as paper or rags,
in the engine compartment.
Do not smoke, cause sparks or al-
low open flames around fuel or the
battery. Their fumes are flammable.
Do not get under your vehicle with
just the body jack supporting it. Al-
ways use automotive jack stands or
other solid supports.
Be sure that the ignition is off if
you work near the electric cooling
fans or radiator grille. With the
ignition on, the electric cooling fans
will automatically start to run if the
engine coolant temperature is high
and/or the air conditioning is on.
Use eye protection whenever you
work on or under your vehicle
where you may be exposed to flying
or falling material, fluid spray, etc.
Used engine oil contains potentially
harmful contaminants which may
cause skin disorders such as in-
flammation or skin cancer, so care
should be taken to avoid prolonged
and repeated contact with it. To re-
move used engine oil from your
skin, wash thoroughly with soap
and water.
Do not leave used oil within the
reach of children.
Dispose of used oil and filter only
in a safe and acceptable manner.
Do not dispose of used oil and fil-
ter in household trash, in sewers or
onto the ground. Call your dealer or
a service station for information
concerning recycling or disposal.
Doityourself service
precautions

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Be extremely cautious when work-
ing on the battery. It contains poi-
sonous and corrosive sulfuric acid.
NOTICE
Remember that battery and ignition
cables carry high currents or volt-
ages. Be careful of accidentally
causing a short circuit.
 Add only demineralized or distilled
water to fill the radiator. And if you
spill some of the coolant, be sure
to wash off with water to prevent it
from damaging the parts or paint.
 Do not allow dirt or anything else
to fall through the spark plug holes.
 Use only spark plugs of the speci-
fied type. Using other types will
cause engine damage, loss of per-
formance or radio noise.
Do not reuse iridiumtipped spark
plugs by cleaning or regapping.
 Do not overfill automatic transmis-
sion fluid and power steering fluid,
or the transmission and power
steering could be damaged.
 Do not drive with the air cleaner
filter removed, or excessive engine
wear could result. Also backfiring
could cause a fire in the engine
compartment.
 Be careful not to scratch the glass
surface with the wiper frame.
 When closing the engine hood,
check to see that you have not for-
gotten any tools, rags, etc.
Front
Rear (twowheel drive models)
Positioning the jack

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DOITYOURSELF MAINTENANCE
Engine and Chassis
Checking the engine oil level456
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level 458
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the radiator and condenser 460
. . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing the air conditioning filter 460
. . . . . . . . . . . . . . .
Checking brake fluid 462
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . .
Checking power steering fluid 463
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking tire inflation pressure 463
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing tires 466
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rotating tires 468
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. . . . . . . . . . .
Run −flat tires 469
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . . . . . .
Installing snow tires and chains 471
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing wheels 473
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \
. . . . . . .
Aluminum wheel precautions 474
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 7 2

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Oil identification marks
Either or both API registered marks are
added to some oil containers to help
you select the oil you should use.
The API Service Symbol is located any-
where on the outside of the container.
The top portion of the label shows the oil
quality by API (American Petroleum Insti-
tute) designations such as SL. The center
portion of the label shows the SAE viscos-
ity grade such as SAE 5W−30. “Energy −
Conserving” shown in the lower portion,
indicates that the oil has fuel −saving ca-
pabilities.
The ILSAC (International Lubricant Stan-
dardization and Approval Committee) Certi-
fication Mark is displayed on the front of
the container.
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 “FULL” and “LOW” lines on the
reservoir. If the level is low, add ethyl-
eneglycol type coolant for a proper
corrosion protection of aluminum com-
ponents.
The coolant level in the reservoir will vary
with engine temperature. However, if the
level is on or below the “LOW” line, add
coolant. Bring the level up to the “FULL”
line.
Always use ethylene
−glycol type coolant
for a proper corrosion protection of alumi-
num 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. Visually check the
radiator, hoses, engine coolant filler cap,
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.
Checking the engine coolant
level

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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. Your coolant
must contain ethylene−glycol type coolant
for proper corrosion protection of your en-
gine that contains aluminum components.
We have used “Toyota Genuine Long Life
Coolant” in your Toyota vehicle. In order
to avoid technical problems, we strongly
recommend using “Toyota Genuine Long
Life Coolant” 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 manufac-
turer’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
489 in Section 8.
We recommend a 50% solution for your
Toyota, to provide protection down to
about
−35 C ( −31 F). When it is extreme-
ly cold, to provide protection down to
about −50 C ( −58 F), a 60% solution is
recommended. Do not use more than 70%
solution for better coolant performance.
NOTICE
Do not use alcohol type antifreeze or
plain water alone.
The engine cooling system is integral to
maximizing performance of your Toyota
vehicle. In line with this, it is strongly
recommended that you use “Toyota
Genuine Long Life Coolant” for protecting
the system, as it is an ethylene −glycol
based premium antifreeze coolant with
excellent corrosion protection properties
that has been specifically formulated for
use in Toyota vehicles.
Please contact your Toyota dealer for fur-
ther details about “Toyota Genuine Long
Life Coolant”.