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Engine Coolant
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-25.
A 50/50 mixture of clean, drinkable water and proper
coolant will:
•Give freezing protection down to−22°F (−30°C).
•Give boiling protection up to 268°F (131°C)
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
What to Use
Use a 50/50 mixture ofclean, drinkable waterand coolant
that meets GM Specification 1825M, which will not
damage aluminum parts. You can also use a recycled
coolant conforming to GM Specification 1825M with a
complete coolant flush and refill. If you use this coolant
mixture, you do not need to add anything else.
For protection in extremely cold weather conditions,
use a 40/60 mixture of clean, drinkable water and proper
coolant.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and the proper coolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
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Checking Coolant
The engine coolant surge tank is located in the rear
of the engine compartment on the driver’s side.
SeeEngine Compartment Overview on page 5-14
for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be between the
MAX (A) and MIN (B) marks on the coolant surge
tank. The level rises at engine operation temperature
and drops again when the engine cools down.
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Adding Coolant
If the level falls below the MIN (B) mark, add the proper
coolant mixtureat the surge tank,but only when the
engine is cool. If the surge tank is empty, a special fill
procedure is necessary. SeeCooling System on
page 5-28for instructions on “How to Add Coolant to
the Coolant Surge Tank.”
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
You will find a coolant temperature gage on your
vehicle’s instrument panel cluster. SeeEngine Coolant
Temperature Gage on page 3-21.
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If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood.
Stay away from the engine if you see or hear
steam coming from it. Just turn it off and get
everyone away from the vehicle until it cools
down. Wait until there is no sign of steam or
coolant before you open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch re.
You or others could be badly burned. Stop
your engine if it overheats, and get out of the
vehicle until the engine is cool.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty.
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If No Steam Is Coming From Your
Engine
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
•Climb a long hill on a hot day.
•Stop after high-speed driving.
•Idle for long periods in traffic.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL
while stopped. If it is safe to do so, pull off the
road, shift to PARK (P) or NEUTRAL and let the
engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning does not come back on, you can drive
normally.
If the warning continues and you have not stopped,
pull over, stop, and park your vehicle right away.
If there is still no sign of steam, you can idle the engine
for three minutes while you are parked. If you still
have the warning,turn off the engine and get everyone
out of the vehicleuntil it cools down.
You may decide not to lift the hood, but to get service
help right away.
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Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank with Pressure Cap
B. Electric Engine Cooling Fan{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
If the coolant inside the coolant surge tank is boiling,
do not do anything else until it cools down. The vehicle
should be parked on a level surface. Make sure that
the air conditioning is turned off.
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The coolant level should be between the MIN (B) and
MAX (A) marks on the coolant surge tank when the
engine is cool. If it is not, you may have a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump or somewhere else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fan is running.
If the engine is overheating, the fan should be running.
If it is not, your vehicle needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
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