2005 CHEVROLET AVALANCHE engine overheat

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 5-30for
information on driving to a safe place in an
emergency.
If No Steam Is Coming From Your
Engine
An overheat warning, 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 4-64.
If you get the overheat warning with no sign of steam, try
this for a minute or so:
1. If your air conditioner 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. If you are in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving — DRIVE (D).
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 right away.
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 three minutes
while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric engine cooling fan, idle the
engine for three 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.
5-29

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 5-15.
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 Fan5300 V8 Engine
5-30

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{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 surge tank is boiling,
do not do anything else until it cools down. 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. 8100 V8 Engine
5-31

When the engine is cold,
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. See
Overheated Engine Protection Operating Mode on
page 5-30for 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.
If your vehicle is equipped with an electric engine
cooling fan, check the coolant temperature gage. If the
coolant temperature is approximately 232°F (111°C),
the electric cooling fan should be running. If it is
not, your vehicle needs service. Turn off the engine.
If your vehicle is equipped with an engine-driven cooling
fan, start the engine again and see if the fan speed
increases when idle speed is doubled by pushing the
accelerator pedal down. If it does not, your vehicle
needs service. Turn off the engine.
5-32

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 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 5-25for 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 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.
{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.
5-33

E
Electrical System...........................................5-103
Center Instrument Panel Fuse Block.............5-106
Fuses and Circuit Breakers.........................5-104
Instrument Panel Fuse Block.......................5-104
Power Windows and Other Power Options....5-104
Underhood Fuse Block...............................5-107
Windshield Wiper Fuses.............................5-104
Engine
Air Cleaner/Filter.........................................5-20
Battery.......................................................5-41
Check and Service Engine Soon Light............3-40
Coolant......................................................5-25
Coolant Heater............................................2-30
Coolant Temperature Gage...........................3-38
Engine Compartment Overview......................5-12
Exhaust.....................................................2-42
Fan Noise..................................................5-35
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-30
Overheating................................................5-28
Starting......................................................2-28
Entry/Exit Lighting...........................................3-18
Event Data Recorders (EDR)............................. 7-9
Extender, Safety Belt.......................................1-28
Exterior Cargo Lamps......................................3-17
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-20
Finish Damage.............................................5-101
Fixed Mast Antenna.......................................3-104
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-74
Flat Tire, Changing.........................................5-75
Flat Tire, Storing.............................................5-91
Fluid
Automatic Transmission................................5-22
Power Steering...........................................5-36
Windshield Washer......................................5-36
Fog Lamps....................................................3-16
Four-Wheel Drive....................................2-34, 5-48
Front Armrest Storage Area..............................2-57
Front Axle......................................................5-49
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
E-85 (85% Ethanol)....................................... 5-6
Filling a Portable Fuel Container..................... 5-9
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-44
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-45
5

N
Navigation/Radio System, see Navigation
Manual......................................................3-89
New Vehicle Break-In......................................2-26
Normal Maintenance Replacement Parts............6-15
O
Odometer......................................................3-31
Off-Road Recovery..........................................4-15
Oil
Engine.......................................................5-15
Pressure Gage............................................3-42
Oil, Engine Oil Life System..............................5-18
Older Children, Restraints................................1-29
Online Owner Center........................................ 7-3
OnStar
®System, see OnStar®Manual...............2-51
Operating Your All-Wheel-Drive Vehicle Off
Paved Roads..............................................4-18
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-28
Outside
Automatic Dimming Mirror with Curb View
Assist.....................................................2-51
Camper-Type Mirrors....................................2-48
Convex Mirror.............................................2-50
Heated Mirrors............................................2-50
Power Mirrors.............................................2-49Overheated Engine Protection
Operating Mode..........................................5-30
Owner Checks and Services.............................. 6-9
Owners, Canadian............................................... ii
P
Park (P)
Shifting Into................................................2-39
Shifting Out of............................................2-41
Parking
Brake........................................................2-38
Over Things That Burn.................................2-41
Passenger Airbag Status Indicator.....................3-32
Passenger Sensing System..............................1-60
Passing.........................................................4-15
Passlock
®......................................................2-26
Power
Accessory Outlets........................................3-19
Door Locks.................................................. 2-9
Electrical System.......................................5-104
Lumbar Controls........................................... 1-3
Retained Accessory (RAP)............................2-27
Seat............................................................ 1-2
Steering Fluid.............................................5-36
Windows....................................................2-23
Programmable Automatic Door Locks.................2-10
9