2007 CHEVROLET IMPALA Owners Manual

whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{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
CAUTION: (Continued)
CAUTION: (Continued)
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®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 coolant needs to be added more than four times
a year, have your dealer/retailer check the
cooling system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system,
you could damage your vehicle. Use only the
proper mixture of the engine coolant listed
in this manual for the cooling system.
SeeRecommended Fluids and Lubricants
on page 417for more information.
321

Checking Coolant
The coolant recovery
tank cap has this
symbol on it.
SeeEngine Compartment Overview on page 306
for more information on the location of the
coolant recovery tank.
The vehicle must be on a level surface when
checking the coolant level.
When the engine is cold, the coolant level
should be at the cold ll line or a little higher.
The cold ll line is marked with the same symbol
as the coolant recovery tank cap.
Adding Coolant
If more coolant is needed, add the proper
DEX-COOL®coolant mixture at the coolant
recovery tank, but be careful not to spill it.
If the coolant recovery tank is completely empty,
add coolant to the cooling system through the
coolant ll neck on the engine. SeeEngine
Overheating on page 323.
{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 — even a
little — when the engine and radiator
are hot.
322

{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.
Occasionally check the coolant level in the
radiator. For information on how to add coolant to
the radiator, seeCooling System on page 326.
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.
SeeEngine Compartment Overview on page 306
for more information on location.
Engine Overheating
There is a coolant temperature gage and a
warning light on the instrument panel that indicate
an overheated engine condition. SeeEngine
Coolant Temperature Gage on page 184
andEngine Coolant Temperature Warning Light
on page 183.
In addition, you will nd an ENGINE
OVERHEATED IDLE ENGINE and an ENGINE
OVERHEATED STOP ENGINE message
displayed on the vehicle’s Driver Information
Center (DIC). SeeDIC Warnings and Messages
on page 199for more information.
323

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. 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 the vehicles
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.
CAUTION: (Continued)
CAUTION: (Continued)
SeeOverheated Engine Protection
Operating Mode on page 326for
information on driving to a safe place in
an emergency.
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. See
Overheated Engine Protection Operating Mode
on page 326for information on driving to a
safe place in an emergency.
324

If No Steam Is Coming From
Your Engine
An overheat warning can indicate a serious
problem.
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.
Tow a trailer.
If an overheat warning occurs without any sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to do
so, pull off the road, shift to PARK (P) or
NEUTRAL (N) and let the engine idle.
2. Set the heater at the highest setting and the
fan at the highest speed and open the
windows as necessary.If the overheat warning no longer exists, the
vehicle can be driven. Just to be safe, drive slower
for about 10 minutes. If the warning does not
come back on, the vehicle can be driven normally.
If the warning continues, and you have not
stopped, pull over, stop, and park the vehicle
right away.
If there is still no sign of steam, idle the engine
for three minutes while parked. If the warning
is still there, turn off the engine and get everyone
out of the vehicle until it cools down. Also, see
“Overheated Engine Protection Operating Mode”
later in this section.
You may decide not to lift the hood but to get
service help right away.
325

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 signicant loss in power and engine
performance. The coolant 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. SeeEngine Oil on page 310.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Recovery Tank
B. Pressure Cap
C. Electric Engine Cooling Fans
3.5L V6 Engine shown, 3.9L Engine similar
326

A. Pressure Cap
B. Electric Engine Cooling Fans
C. Coolant Recovery Tank
{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, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
If your vehicle has one of the V6 engines, the
coolant recovery tank is located in the rear of the
engine compartment on the passenger’s side of the
vehicle. If your vehicle has the 5.3L V8 engine, the
coolant recovery tank is located in the rear of the
engine compartment on the driver’s side of the
vehicle. SeeEngine Compartment Overview on
page 306.
5.3L V8 Engine
327

When the engine is cold, the coolant level should
be at or above the cold ll line on the coolant
recovery tank. To check the coolant level, look
for the cold ll line on the side of the coolant
recovery tank that faces the engine. If the level is
not correct, there may be 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 fans
are running. If the engine is overheating, the fans
should be running. If the fans are not running,
your vehicle needs service.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 326for information on
driving to a safe place in an emergency.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant could require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
328