engine overheat GMC ENVOY 2005 User Guide

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant. If you use this coolant
mixture, you don’t 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 engine coolant
recovery tank is in the
engine compartment
on the passenger’s side of
the vehicle. The cap
has this symbol on it.
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 FULL
COLD, or a little higher.
5-26

Radiator 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 5-12for
information on location.
Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. If your vehicle has a Driver
Information Center (DIC), the display will show an
Engine Coolant Hot or Engine Overheated message.
SeeDIC Warnings and Messages on page 3-55
for more information.
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. Just 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 your 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.
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.
5-28

If No Steam Is Coming From Your
Engine
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 you get the overheat warning with no 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. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.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 and you have not stopped, pull
over, stop, and park your vehicle right away.
If there is still no sign of steam, you can 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 you still have the warning,turn off
the engine and get everyone out of the vehicleuntil it
cools down.
You may decide not to lift the hood but to get service
help right away.
5-29

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 FULL COLD mark, add a
50/50 mixture ofclean, drinkable waterand DEX-COOL
®
engine coolant at the coolant recovery tank. See
Engine Coolant on page 5-25for more information.
{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
FULL COLD mark, start your vehicle.
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.
5-32

E
Electrical System
Add-On Equipment......................................5-96
Engine Compartment Fuse Block...................5-97
Fuses and Circuit Breakers...........................5-97
Headlamps.................................................5-96
Power Windows and Other Power Options......5-96
Rear Underseat Fuse Block.........................5-106
Windshield Wiper Fuses...............................5-96
Engine
Air Cleaner/Filter.........................................5-20
Battery.......................................................5-41
Change Engine Oil Light...............................3-46
Check and Service Engine Soon Light............3-42
Coolant......................................................5-25
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-41
Engine Compartment Overview......................5-12
Exhaust.....................................................2-34
Fan Noise..................................................5-35
Oil .............................................................5-16
Overheating................................................5-28
Reduced Power Light...................................3-47
Starting......................................................2-20
Entry Lighting.................................................3-19
Event Data Recorders (EDR)............................7-10
Exit Lighting...................................................3-19
Extender, Safety Belt.......................................1-26
F
Filter
Engine Air Cleaner......................................5-20
Finish Damage...............................................5-93
Fixed Mast Antenna.......................................3-139
Flash-to-Pass................................................... 3-8
Flat Tire........................................................5-70
Flat Tire, Changing.........................................5-71
Flat Tire, Storing.............................................5-82
Fluid
Automatic Transmission................................5-22
Power Steering...........................................5-36
Windshield Washer......................................5-36
Fog Lamps....................................................3-17
Four-Wheel Drive....................................2-26, 5-48
Front Axle......................................................5-48
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Check Gas Cap Light...................................3-51
Filling a Portable Fuel Container..................... 5-9
Filling Your Tank........................................... 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-50
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-51
5