cooling CHEVROLET IMPALA 2005 8.G User Guide

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended 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, seeEngine Overheating on page 5-32.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
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.
5-29

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 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 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.
Checking Coolant
The coolant recovery tank
is located between the
power steering uid
reservoir and the
underhood fuse block, in
the engine compartment,
on the passenger’s
side of the vehicle.
SeeEngine Compartment
Overview on page 5-12
for more information
on location.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
COLD mark or a little higher. When your engine is
warm, the level should be up to the HOT mark or
a little higher.
5-30

Adding Coolant
If you need more coolant, 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 radiator. SeeEngine Overheating on
page 5-32.
{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.
{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 5-34.
Radiator Pressure Cap
Notice:The radiator cap on your vehicle 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 overow tube on the radiator ller neck.
The radiator pressure cap is located in the front of the
engine compartment on the passenger’s side of the
vehicle, near the diagonal cross brace. SeeEngine
Compartment Overview on page 5-12for more
information on location.
5-31

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 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. SeeEngine Oil
on page 5-18.
Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans
C. Radiator Pressure Cap3400 V6 Engine
5-34

A. Engine Coolant Recovery Tank
B. Electric Engine Cooling Fans
C. Radiator Pressure Cap
{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.
The coolant recovery tank is located in the rear of the
engine compartment on the passenger’s side of the
vehicle. SeeEngine Compartment Overview on
page 5-12. 3800 V6 Engine shown, 3800 V6 Supercharged
Engine similar
5-35

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 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 fans are running.
If the engine is overheating, both fans should be
running. If they are not, 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 5-34for 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 may
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.
5-36

How to Add Coolant to the Coolant
Recovery Tank
If you have not found a problem yet, but the coolant
level is not at the COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®engine
coolant at the coolant recovery tank. SeeEngine
Coolant on page 5-29.
{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 DEX-COOL
®
coolant.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 in the coolant recovery tank is at the
COLD mark, start your vehicle.
5-37

If the overheat warning continues, there is 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.
{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 Radiator
Notice:Your engine has a specic radiator ll
procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.
1. You can remove the radiator pressure cap when
the cooling system, including the radiator pressure
cap and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise until
it rst stops. Do not 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.
5-38

10. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.11. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
12. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the arrow on the pressure cap lines up properly.
13. Check the coolant in the recovery tank. The level in
the coolant recovery tank should be at the HOT
mark when the engine is hot or at the COLD mark
when the engine is cold.
5-42

Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle.
{CAUTION:
Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-78for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
5-75