engine overheat GMC ENVOY XL 2004 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.
5-25

Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. If your vehicle has a DIC,
the display will show an Engine Coolant Hot or
Engine Overheated message.
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 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 window 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 doesn’t 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’s 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’re 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 haven’t found a problem yet, but the coolant level
isn’t at the FULL COLD mark, add a 50/50 mixture of
clean, drinkable waterand DEX-COOL
®engine coolant
at the coolant recovery tank. SeeEngine Coolant on
page 5-24for 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.
5-32

Driving (cont.)
Hill and Mountain Roads..............................4-38
In Rain and on Wet Roads...........................4-31
Winter........................................................4-40
Driving Across an Incline..................................4-26
Driving Downhill..............................................4-24
Driving in Mud, Sand, Snow or Ice....................4-28
Driving in Water..............................................4-28
Driving On Grades..........................................4-63
Driving on Off-Road Hills.................................4-21
Driving on Snow or Ice....................................4-41
Driving Through Deep Standing Water...............4-33
Driving Through Flowing Water.........................4-33
Driving Uphill..................................................4-22
Driving with a Trailer.......................................4-61
Dual Automatic Climate Control System.............3-25
Dual Climate Control System............................3-22
DVD
Rear Seat Entertainment System..................3-106
DVD Distortion..............................................3-117
DVD Messages.............................................3-117
DVD Player..................................................3-110
E
Electrical System
Add-On Equipment......................................5-96
Fuses and Circuit Breakers...........................5-97
Headlamps.................................................5-96Electrical System (cont.)
Power Windows and Other Power Options......5-96
Windshield Wiper Fuses...............................5-96
Electronically Controlled Air Suspension
System......................................................4-54
Emergency Release for Opening Liftgate............2-14
Emissions Inspection and Maintenance
Programs...................................................3-45
Engine
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-42
Change Engine Oil Light...............................3-47
Check and Service Engine Soon Light............3-43
Coolant......................................................5-24
Coolant Heater............................................2-23
Coolant Temperature Gage...........................3-42
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-12
Exhaust.....................................................2-34
Fan Noise..................................................5-36
Oil .............................................................5-16
Overheating................................................5-28
Reduced Power Light...................................3-48
Starting......................................................2-21
Engine Compartment Fuse Block......................5-97
ENGINE COOLANT HOT/ENGINE
OVERHEATED............................................3-61
Engine Oil Additives........................................5-19
Entry Lighting.................................................3-19
Environmental Concerns..................................4-18
5