2003 CHEVROLET IMPALA Owners Manual

Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans
C. Radiator Pressure CapA. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans
C. Radiator Pressure Cap
3400 V6 Engine
3800 V6 Engine
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{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 recovery tank is boiling,
don't do anything else until it cools down. The vehicle
should be parked on a level surface.
The coolant level should
be at or above the COLD
mark on the coolant
recovery tank.To check the coolant level, look for the COLD mark on
the side of the coolant recovery tank that faces the
engine. When the engine is cold, the coolant level
should be at or above the COLD mark on the coolant
recovery tank. If it isn't, 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. Don't touch them. If you
do, you can be burned.
Don't 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 fans are running.
If the engine is overheating, both fans should be
running. If they aren't, your vehicle needs service.
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Notice:Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index for information on driving to a
safe place in an emergency.
Notice:When adding coolant, it is important that
you use only DEX-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50 000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new
vehicle warranty.
How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the COLD mark, add a 50/50 mixture ofclean,
drinkable waterand DEX-COOLžengine coolant at
the coolant recovery tank. SeeEngine Coolant on
page 5-27
{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 wouldn't 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 DEX-COOL
žcoolant.
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Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
The coolant recovery tank is located in the rear of the
engine compartment on the passenger's side of the
vehicle. See
Engine Compartment Overview on
page 5-12
{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. Don't spill coolant on a hot engine.
When the coolant in the coolant recovery tank is at the
COLD mark, start your vehicle.
If the overheat warning continues, there's one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
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{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator
pressure cap -- even a little -- they can come
out at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have
to turn the pressure cap.
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How to Add Coolant to the Radiator
Notice:Your engine has a speci®c radiator
®ll procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.The radiator pressure cap is located in the front of the
engine compartment near the diagonal cross brace
on the passenger's side of the vehicle. SeeEngine
Compartment Overview on page 5-12
1. Turn the pressure cap slowly counterclockwise until
it ®rst stops. (Don't press down while turning the
pressure cap.)
If you hear a hiss, wait for that to stop. A hiss
means there is still some pressure left.
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2. Then keep turning the pressure cap, but now push
down as you turn it. Remove the pressure cap.
{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. Don't spill coolant on a hot engine.3. If you have the 3800 V6 engine, remove the
3800 Series II V6 engine cover shield to access the
bleed valve.
3.1. Clean the area around the engine oil ®ll tube
and cap before removing. Twist the oil ®ll
tube, with cap attached, counterclockwise
and remove it.
3.2. Lift the engine cover shield at the front, slide
the catch tab out of the engine bracket and
remove the cover shield.
3.3. Put the oil ®ll tube, with cap attached, in the
valve cover oil ®ll hole until you're ready to
replace the cover shield.
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4. After the engine cools, open the coolant air bleed
valve or valves.
3400 V6 engine: There are two bleed valves. One
is located on the thermostat housing. The other
is located on the thermostat bypass tube.3800 V6 engine: There is one bleed valve. It is
located on the thermostat housing. 3400 V6 BLEED
VALVE #1
3400 V6 BLEED
VALVE #2
3800 Series II V6 Bleed Valve
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