2007 CHEVROLET AVALANCHE engine coolant

Adding Coolant
If you need more coolant, add the proper
DEX-COOL®coolant mixture at the surge tank,
but only when the engine is cool. SeeCooling
System on page 464.
{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 replacing the pressure cap, make sure
it is hand-tight and fully seated.
Coolant Surge Tank 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.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 444for more
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 249.
In addition, you will nd an ENGINE
OVERHEATED STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and an ENGINE
POWER IS REDUCED message in the Driver
Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 267.
460

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 463for
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 463for information on driving to a
safe place in an emergency.
461

If No Steam Is Coming From
Your Engine
The ENGINE OVERHEATED STOP ENGINE
or the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant condition,
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. SeeTowing a Trailer
on page 414.If you get the ENGINE OVERHEATED STOP
ENGINE or the ENGINE OVERHEATED IDLE
ENGINE message with no sign of steam, try this
for a minute or so:
1. If you have an air conditioner and it is on,
turn it off.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. 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.
If you no longer have the overheat warning,
you can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not
come back on, you can drive normally.
If the warning continues, pull over, stop, and
park your vehicle immediately.
462

If there is still no sign of steam and your vehicle
is equipped with an engine-driven cooling fan,
push down the accelerator until the engine speed
is about twice as fast as normal idle speed for
at least ve minutes while you are parked.
If there is still no sign of steam and your vehicle
is equipped with an electric cooling fan, idle
the engine for ve minutes while you are parked.
If you still have the warning, 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
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is
displayed, an overheat protection mode which
alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a
loss in power and engine performance. This
operating mode allows your vehicle to be driven to
a safe place in an emergency. 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 446.
463

Cooling System
When you decide it is safe to lift the hood,
here is what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s){CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
If possible, the vehicle should be parked on a
level surface. Check the coolant level after
the system cools down. Some amount of coolant
may be lost due to overheating.
5.3L Engine (6.0L Similar)
464

The coolant level should be at or above the FULL
COLD mark. 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.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 463for 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.
465

How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to
see if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at or above
the FULL COLD mark, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®
coolant at the coolant surge tank, but be sure
the cooling system, including the coolant surge
tank pressure cap, is cool before you do it.
SeeEngine Coolant on page 457for more
information.
If no coolant is visible in the surge tank,
add coolant as follows:
{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 coolant surge tank pressure
cap — even a little — they can come out at
high speed. Never turn the cap when the
cooling system, including the coolant
surge tank pressure cap, is hot. Wait for
the cooling system and coolant surge
tank pressure cap to cool if you ever
have to turn the pressure cap.
466

{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.
1. You can remove
the coolant surge
tank pressure
cap when the
cooling system,
including the
coolant surge tank
pressure cap and
upper radiator hose,
is no longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn. If you hear a hiss, wait for
that to stop. A hiss means there is still some
pressure left.
467