2004 GMC ENVOY radiator

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 5-25for 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.
5-32

When the coolant in the coolant recovery tank is at the
FULL COLD mark, start your vehicle.
If the overheat warning continues, there’s 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.
{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.
5-33

How to Add Coolant to the Radiator
1. You can remove the radiator pressure cap when
the cooling system, including the radiator 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.2. Then keep turning the pressure cap. Remove the
pressure cap.
5-34

3. Fill the radiator with the proper DEX-COOL®
coolant mixture, up to the base of the ller
neck. SeeEngine Coolant on page 5-25for more
information about the proper coolant mixture.4. Then ll the coolant recovery tank to the FULL
COLD mark.
5. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.
5-35

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the pressure cap is hand-tight.
Engine Fan Noise
This vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions
the clutch is not engaged. This improves fuel economy
and reduces fan noise. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, the fan
speed increases when the clutch engages. So you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional cooling
is not required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
5-36

(c)Visually inspect hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken air bag
coverings, and have them repaired or replaced. (The air
bag system does not need regular maintenance.)
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer liftgate handle pivot
points, rear door detent link, roller mechanism, liftgate
handle pivot points, latch bolt, fuel door hinge, cargo
door hinge, locks and folding seat hardware. More
frequent lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better and not stick or squeak.(g)Add uid as needed. A uid loss could indicate a
problem; repair as needed. Check vent hose at transfer
case for kinks and proper installation.
(h)Change automatic transmission uid and lter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-25for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the uid level checked. Add uid if needed.
6-8

Horn............................................................... 3-7
How to Add Coolant to the
Coolant Recovery Tank................................5-32
How to Add Coolant to the Radiator..................5-34
How to Add Fluid............................................5-25
How to Check........................................5-23, 5-66
How to Check Lubricant...................................5-49
How to Check Power Steering Fluid..................5-37
How to Inspect...............................................5-22
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-14
Hydroplaning..................................................4-31
I
ICE POSSIBLE..............................................3-61
If No Steam Is Coming From Your Engine..........5-29
If Steam Is Coming From Your Engine...............5-28
If the Light Is Flashing.....................................3-41
If the Light Is On Steady.................................3-42
If You Are Caught in a Blizzard.........................4-40
If You Are Stuck in Sand, Mud, Ice or Snow.......4-42
If You Do Decide To Pull A Trailer.....................4-56
Ignition Positions.............................................2-20
Infants and Young Children, Restraints...............1-31
Ination - Tire Pressure...................................5-65Instrument Panel
Cluster.......................................................3-33
Overview..................................................... 3-4
Instrument Panel Brightness.............................3-17
Interior Lamps................................................3-17
J
Jump Starting.................................................5-43
K
Keyless Entry System....................................... 2-5
Keys............................................................... 2-3
L
Lamps
Exterior......................................................3-15
Interior.......................................................3-17
Lamps On Reminder.......................................3-16
Lap-Shoulder Belt...................................1-14, 1-23
LATCH System
Child Restraints...........................................1-42
Securing a Child Restraint Designed for the
LATCH System........................................1-44
8

R
Radiator Pressure Cap....................................5-27
Radio Data System (RDS)...............3-64, 3-76, 3-90
Radio Messages.....................................3-70, 3-81
Radios..........................................................3-63
Care of Your Cassette Tape Player...............3-118
Care of Your CD and DVD Player................3-119
Care of Your CDs and DVDs.......................3-119
Navigation/Radio System.............................3-103
Radio Personalization.................................3-115
Radio with Cassette and CD.........................3-75
Radio with CD............................................3-64
Radio with Six-Disc CD................................3-90
Rear Seat Audio........................................3-114
Setting the Time..........................................3-63
Theft-Deterrent..........................................3-116
Understanding Reception............................3-117
Rainsense™ Wipers........................................3-10
RDS Messages..............................3-69, 3-80, 3-94
Reading Lamps..............................................3-18
REAR ACCESS OPEN....................................3-61
Rear Axle......................................................5-49
Locking......................................................4-10
Rear Climate Control System............................3-28
Rear Compartment Storage Panel/Cover............2-48Rear Door Security Locks................................2-13
Rear Floor Storage Lid....................................2-50
Rear Safety Belt Comfort Guides......................1-25
Rear Seat Audio (RSA)..................................3-114
Rear Seat Entertainment System.....................3-104
Rear Seat Operation......................................... 1-5
Rear Seat Passenger Positions.........................1-22
Rear Seat Passengers, Safety Belts..................1-22
Rear Seats (Envoy XL)..................................... 1-7
Rear Storage Area..........................................2-48
Rear Underseat Fuse Block............................5-109
Rear Window Defogger............................3-22, 3-27
Rearview Mirror, Automatic Dimming with
OnStar
®and Compass.................................2-36
Reclining Seatbacks, Power............................... 1-4
Recommended Fluids and Lubricants.................6-12
Recreational Vehicle Towing.............................4-44
Reduced Engine Power Light............................3-46
Remote Control.............................................3-107
Remote Keyless Entry System............................ 2-5
Remote Keyless Entry System, Operation............ 2-6
Removing the Flat Tire and
Installing the Spare Tire................................5-83
Removing the Spare Tire and Tools...................5-77
Replacement Bulbs.........................................5-54
Replacing Brake System Parts..........................5-42
12