2008 CHEVROLET IMPALA engine overheat

{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 5-32.
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 5-14for
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 3-38andEngine Coolant Temperature
Warning Light on page 3-37.
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 3-52for more information.
5-29

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.
SeeOverheated Engine Protection Operating
Mode on page 5-31for 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. SeeOverheated Engine Protection
Operating Mode on page 5-31for information on
driving to a safe place in an emergency.
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.
5-30

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.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 5-17.
5-31

{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 5-14.
When the engine is cold, the coolant level should be at
or above the COLD FILL line on the coolant recovery
tank. To check the coolant level, look for the COLD FILL
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 5-31for 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 the warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
5-33

How to Add Coolant to the Coolant
Recovery Tank
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.If you have not found a problem yet, but the coolant
level is not at the COLD FILL line, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®engine
coolant at the coolant recovery tank. SeeEngine
Coolant on page 5-26for more information.
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.
{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 the coolant level in the coolant recovery tank is at
the COLD FILL line, start the vehicle.
5-34

If the overheat warning continues, there is one more
thing you can try. You can add the proper coolant
mixture directly to the cooling system through the
coolant ll neck on the engine, but be sure the system
is cool before you do it.
{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.
How to Add Coolant to the Cooling
System
Notice:The engine has a specic cooling system
drain and ll procedure. Failure to follow this
procedure could cause the engine to overheat and
be severely damaged. If the engine’s cooling system
needs to be drained and re-lled, please see the
dealer/retailer.
1. You can remove the
pressure cap when
the cooling system,
including the pressure
cap and upper radiator
hose is no longer hot.
Turn the pressure
cap slowly
counterclockwise.
If you hear a hiss, wait for that to stop. A hiss
means that there is still some pressure left.
2. Then keep turning the pressure cap and remove it.
5-35

Engine
Air Cleaner/Filter.........................................5-22
Check and Service Engine Soon Light............3-39
Coolant......................................................5-26
Coolant Heater............................................2-25
Coolant Temperature Gage...........................3-38
Coolant Temperature Warning Light................3-37
Drive Belt Routing.......................................6-14
Engine Compartment Overview......................5-14
Exhaust.....................................................2-34
Oil .............................................................5-17
Oil Life System...........................................5-20
Overheated Protection Operating Mode...........5-31
Overheating................................................5-29
Running While Parked..................................2-34
Starting......................................................2-23
Entry Lighting.................................................3-17
Event Data Recorders.....................................7-17
Extender, Safety Belt.......................................1-30
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-22
Finish Damage...............................................5-96
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-77
Flat Tire, Changing.........................................5-78
Flat Tire, Storing.............................................5-87
Fluid
Automatic Transmission................................5-24
Power Steering...........................................5-37
Windshield Washer......................................5-38
Fog Lamp
Fog ...........................................................3-16
Fog Lamp Light..............................................3-42
Folding Rear Seat............................................ 1-8
Fuel............................................................... 5-5
Additives...................................................... 5-7
California Fuel.............................................. 5-6
E85 (85% Ethanol)........................................ 5-8
Filling a Portable Fuel Container....................5-12
Filling the Tank...........................................5-10
Fuels in Foreign Countries.............................. 5-9
Gage.........................................................3-43
Gasoline Octane........................................... 5-6
Gasoline Specications.................................. 5-6
Fuses
Fuses and Circuit Breakers...........................5-99
Instrument Panel Fuse Block.........................5-99
Underhood Fuse Block...............................5-100
Windshield Wiper.........................................5-99
5

O
Odometer......................................................3-29
Off-Road Recovery..........................................4-11
Oil
Engine.......................................................5-17
Pressure Light.............................................3-42
Oil, Engine Oil Life System..............................5-20
Older Children, Restraints................................1-31
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-18
OnStar
®System, see OnStar®Manual...............2-38
Operation, Universal Home Remote System........2-42
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-25
Outlets
Accessory Power.........................................3-20
Outside
Convex Mirror.............................................2-37
Power Heated Mirrors..................................2-37
Power Mirrors.............................................2-37
Overheated Engine Protection Operating Mode.....5-31
Owner Checks and Services.............................. 6-8
Owners, Canadian............................................... ii
P
Paint, Damage...............................................5-96
Parade Dimming.............................................3-18
Park Brake....................................................2-30
Park (P)
Shifting Into................................................2-30
Shifting Out of............................................2-32
Parking
Over Things That Burn.................................2-33
Passenger Airbag Status Indicator.....................3-32
Passenger Compartment Air Filter.....................3-26
Passenger Sensing System..............................1-62
Passing.........................................................4-11
PASS-Key
®III+..............................................2-19
PASS-Key®III+ Operation................................2-20
Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................2-11
Electrical System.........................................5-99
Retained Accessory (RAP)............................2-23
Seat............................................................ 1-3
Steering Fluid.............................................5-37
Windows....................................................2-16
Pressure Cap.................................................5-29
9