2003 CHEVROLET IMPALA overheating

Engine Coolant Temperature GageThis gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During the majority of the operation, the
gage will read 210ÉF (100ÉC) or less.
If you are pulling a load or going up hills, it is normal for
the temperature to ¯uctuate and approach the 250ÉF
(122ÉC) mark. When the gage reads greater than 250ÉF
(122ÉC), the HOT COOLANT TEMP light will be
illuminated in the message center and a chime will
sound continuously. If the gage reaches the 260ÉF
(125ÉC) mark, it indicates that the cooling system is
working beyond its capacity.
See
Engine Overheating on page 5-30.
United States±3400 V6
Engine ClusterUnited States±3800 V6
Engine Cluster
Canada±3400 V6 Engine
ClusterCanada±3800 V6 Engine
Cluster
3-36

Battery Warning Message
When the vehicle is started
this message will be
displayed for three
seconds.
If the message is displayed when the engine is running,
you may have a problem with your charging system.
If there is a problem with the charging system, four
chimes will sound when the message comes on. The
battery display will also stay on while the key is in
ON until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or
some other charging system problem. Have it checked
right away. Driving with this message on could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories.
Hot Coolant Temperature Warning
Message
This message is displayed when the cooling
system temperature gets hot. A chime will sound
continuously, also.
Check the coolant temperature gage and the coolant
level. See
Engine Coolant on page 5-27,Engine Coolant
Temperature Gage on page 3-36andEngine
Overheating on page 5-30for further information.
United StatesCanada
3-42

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need additional
wiring. Check with your dealer. The arrows on your
instrument panel will ¯ash whenever you signal a turn or
lane change. Properly hooked up, the trailer lamps
will also ¯ash, telling other drivers you're about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ¯ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It's
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
On a long uphill grade, shift down and reduce your
speed to around 45 mph (70 km/h) to reduce the
possibility of engine and transaxle overheating.
If you have overdrive, you may want to drive in
THIRD (3) instead of AUTOMATIC OVERDRIVE
X.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift to PARK (P).
5. Release the regular brakes.
4-39

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
·start your engine,
·shift into a gear, and
·release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store
the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transaxle ¯uid (don't over®ll),
engine oil, drive belts, cooling system and brake system.
Each of these is covered in this manual, and the
Index will help you ®nd them quickly. If you're trailering,
it's a good idea to review this information before you
start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-30.
4-40

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-22
Automatic Transaxle Fluid..............................5-24
Engine Coolant.............................................5-27
Radiator Pressure Cap..................................5-30
Engine Overheating.......................................5-30
Cooling System............................................5-33
Power Steering Fluid.....................................5-43
Windshield Washer Fluid................................5-44
Brakes........................................................5-45Battery........................................................5-48
Jump Starting...............................................5-49
Headlamp Aiming...........................................5-55
Bulb Replacement..........................................5-56
Halogen Bulbs..............................................5-56
Headlamps, Front Turn Signal, and Parking
Lamps.....................................................5-56
Taillamps, Turn Signal, Stoplamps and
Sidemarker Lamps.....................................5-58
Back-Up Lamps............................................5-59
Replacement Bulbs.......................................5-59
Windshield Wiper Blade Replacement..............5-60
Tires..............................................................5-61
In¯ation -- Tire Pressure................................5-62
Tire Pressure Monitor System.........................5-63
Tire Inspection and Rotation...........................5-65
When It Is Time for New Tires.......................5-66
Buying New Tires.........................................5-67
Uniform Tire Quality Grading..........................5-68
Wheel Alignment and Tire Balance..................5-69
Wheel Replacement......................................5-69
Tire Chains..................................................5-71
If a Tire Goes Flat........................................5-71
Changing a Flat Tire.....................................5-72
Compact Spare Tire......................................5-84
Section 5 Service and Appearance Care
5-1

Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating or if you need to add coolant to
your radiator, see
Engine Overheating on page 5-30.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
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 -- 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.
5-27

Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the coolant recovery tank,but be
careful not to spill it.
If the coolant recovery tank is completely empty, add
coolant to the radiator. See
Engine Overheating
on page 5-30.
{CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. With the coolant recovery tank, you will
almost never have to add coolant at the
radiator. Never turn the radiator pressure
cap Ð even a little Ð when the engine and
radiator are hot.
{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.
Occasionally check the coolant level in the radiator. For
information on how to add coolant to the radiator,
see
Cooling System on page 5-33.
5-29

Radiator Pressure Cap
Notice:Your radiator cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
Be sure the arrows on the cap line up with the
over¯ow tube on the radiator ®ller neck.
The radiator pressure cap is located in the front of the
engine compartment on the passenger's side, near
the diagonal cross brace. See
Engine Compartment
Overview on page 5-12for more information on location.
Engine Overheating
You will ®nd a coolant temperature gage and a warning
message about a hot engine on your instrument
panel cluster. See
Engine Coolant Temperature Gage
on page 3-36andHot Coolant Temperature Warning
Message on page 3-42.
Overheated Engine Protection
Operating Mode
This emergency operating mode allows your vehicle to
be driven to a safe place in an emergency situation.
If an overheated engine condition exists, an overheat
protection mode which alternates ®ring groups of
cylinders helps prevent engine damage. In this mode,
you will notice a signi®cant loss in power and engine
performance. The low coolant light may come on
and the temperature gage will indicate an overheat
condition exists. Driving extended miles (km) and/or
towing a trailer in the overheat protection mode should
be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil
and reset the oil life system. See ªEngine Oilº in
the Index.
5-30