2006 CHEVROLET SUBURBAN engine overheat

If No Steam Is Coming From
Your Engine
The ENGINE COOLANT HOT 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 4-62.
If you get the ENGINE COOLANT HOT 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 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 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 Fan8.1L V8 Engines
5-30

A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{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. 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.
All Other Engines
5-31

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.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.
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.
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 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 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 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.
{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

Engine (cont.)
Engine Compartment Overview......................5-12
Exhaust.....................................................2-36
Fan Noise..................................................5-35
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-30
Overheating................................................5-28
Starting......................................................2-20
Entry Lighting.................................................3-19
Event Data Recorders (EDR)............................7-10
Exit Lighting...................................................3-19
Extender, Safety Belt.......................................1-47
F
Filter
Engine Air Cleaner......................................5-20
Finish Damage.............................................5-106
Fixed Mast Antenna.......................................3-133
Flashers, Hazard Warning.................................. 3-5
Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-78
Flat Tire, Changing.........................................5-79
Flat Tire, Storing.............................................5-94Fluid
Automatic Transmission................................5-22
Power Steering...........................................5-36
Windshield Washer......................................5-37
Fog Lamps ....................................................3-17
Four-Wheel Drive....................................2-26, 5-48
Four-Wheel-Drive Light....................................3-49
Front Axle......................................................5-50
Front Reading Lamps......................................3-19
Front Storage Area.........................................2-56
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
E85 (85% Ethanol)........................................ 5-7
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-8
Gage .........................................................3-50
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-50
Fuses
Center Instrument Panel Fuse Block.............5-112
Fuses and Circuit Breakers.........................5-109
Instrument Panel Fuse Block.......................5-110
Underhood Fuse Block...............................5-113
Windshield Wiper.......................................5-109
6

Mirrors (cont.)
Automatic Dimming Rearview with OnStar®
and Compass..........................................2-37
Automatic Dimming Rearview with OnStar®,
Compass and Temperature Display.............2-39
Manual Rearview Mirror................................2-37
Outside Automatic Dimming Mirror.................2-48
Outside Camper-Type Mirrors........................2-46
Outside Convex Mirror.................................2-49
Outside Curb View Assist Mirrors...................2-49
Outside Heated Mirrors................................2-49
Outside Manual Mirrors................................2-46
Outside Power Foldaway Mirrors....................2-48
Outside Power Mirrors..................................2-47
MyGMLink.com................................................ 7-4
N
Navigation/Radio System, see Navigation
Manual.....................................................3-117
New Vehicle Break-In......................................2-18
Normal Maintenance Replacement Parts............6-14
O
Odometer......................................................3-36
Odometer, Trip...............................................3-36
Off-Road Driving.............................................4-17
Off-Road Recovery..........................................4-14
Oil
Engine.......................................................5-15
Pressure Gage............................................3-48
Oil, Engine Oil Life System..............................5-18
Older Children, Restraints................................1-48
Online Owner Center........................................ 7-4
OnStar
®System, see OnStar®Manual...............2-50
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-30
Outlet(s), Accessory Power...............................3-20
Outside
Automatic Dimming Mirror.............................2-48
Camper-Type Mirrors....................................2-46
Convex Mirror.............................................2-49
Curb View Assist Mirrors..............................2-49
Heated Mirrors............................................2-49
Manual Mirrors............................................2-46
Power Foldaway Mirrors...............................2-48
Power Mirrors.............................................2-47
Overheated Engine Protection Operating Mode.....5-30
Owner Checks and Services.............................. 6-9
Owners, Canadian............................................... ii
10