1999 TOYOTA SIENNA radiator

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If your vehicle overheats
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 the
radiator, 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 temperature
has 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 should have it checked as
soon as possible at your Toyota dealer.
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If you perform maintenance by yourself,
be sure to follow the correct procedure
given in this part.
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 part gives instructions only for those
items that are relatively easy for an owner
to perform. As explained in Part 6, there
are still a number of items that must be
done by a qualified technician with special
tools.
For information on tools and parts for do−
it−yourself maintenance, see ”Parts and
tools”.
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 smoke, cause sparks or al-
low open flames around fuel or the
battery. Their fumes are flammable.
Be extremely cautious when work-
ing on the battery. It contains poi-
sonous and corrosive sulfuric acid.
Do not get under your vehicle with
just the body jack supporting it. Al-
ways use automotive jack stands or
other solid supports.
Do−it−yourself service
precautions
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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.
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.
Do not pry the outer electrode of a
spark plug against the center elec-
trode.
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 platinum−tipped spark
plugs by cleaning or regapping.
Do not overfill automatic transmis-
sion fluid, or the transmission
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.
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Look at the see−through 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-
ene−glycol 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.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 a proper corrosion protection of your
engine that contains aluminum
components. Use ”Toyota 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 in Part 8.We recommend to use 50% solution for
your Toyota, to provide protection down to
about −35C (−31F). When it is extreme-
ly cold, to provide protection down to
about −50°C (−58°F), 60% solution is rec-
ommended. Do not use more than 70%
solution for better coolant performance.NOTICE
Do not use alcohol type antifreeze or
plain water alone.
Checking the engine coolant
level
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