2005 GMC ENVOY engine overheat

To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver’s side of the
engine compartment, behind the battery.
3. Plug it into a normal, grounded 110-Volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could
be damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer in the area where you will be parking
your vehicle. The dealer can give you the best advice
for that particular area.
2-22

Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
If you have four-wheel drive, your vehicle will be
free to roll — even if your lever is in
PARK (P) — if your transfer case is in
NEUTRAL. So be sure the transfer case is in a
drive gear — not NEUTRAL. SeeFour-Wheel
Drive on page 2-26.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running unless
you have to.If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and your
parking brake is rmly set before you leave it. After you
have moved the shift lever into PARK (P), hold the
regular brake pedal down. Then, see if you can move
the shift lever away from PARK (P) without rst pressing
the button on the console shift lever. If you can, it
means that the shift lever was not fully locked into
PARK (P).
Torque Lock
If you are parking on a hill and you do not shift your
transmission into PARK (P) properly, the weight of the
vehicle may put too much force on the parking pawl
in the transmission. You may nd it difficult to pull the
shift lever out of PARK (P). This is called “torque
lock.” To prevent torque lock, set the parking brake and
then shift into PARK (P) properly before you leave
the driver’s seat. To nd out how, seeShifting Into
Park (P) on page 2-31.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission, so
you can pull the shift lever out of PARK (P).
2-32

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds. That’s
normal. A chime may also
sound when the light
comes on.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. If the regular brake
system warning light isn’t on, you still have brakes, but
you don’t have anti-lock brakes. If the regular brake
system warning light is also on, you don’t have anti-lock
brakes and there’s a problem with your regular
brakes. SeeBrake System Warning Light on page 3-40
earlier in this section.
The anti-lock brake system warning light should come
on briey when you turn the ignition key to RUN. If
the light doesn’t come on then, have it xed so it will be
ready to warn you if there is a problem.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, it means that
your engine coolant has overheated. If you have been
operating your vehicle under normal driving conditions,
you should pull off the road, stop your vehicle and
turn off the engine as soon as possible.
SeeEngine Overheating on page 5-28for
more information.
United StatesCanada
3-41

BATTERY NOT CHARGING
If the battery is not charging during operation, this
message will appear on the DIC. Driving with this
problem could drain your battery. Have the electrical
system checked by your GM dealer as soon as possible.
SeeVoltmeter Gage on page 3-39. Press the select
button to acknowledge this message and clear it from
the DIC display.
CHECK WASHER FLUID
If the washer uid level is low, this message will appear
on the DIC. Adding washer uid will clear the message.
SeeWindshield Washer Fluid on page 5-36. Press
the select button to acknowledge this message and clear
it from the DIC display.
CURB VIEW ACTIVATED
The CURB VIEW ACTIVATED message is displayed
when the passenger outside rearview mirror moves into
the curb view position. SeeOutside Curb View Assist
Mirror on page 2-46for more information.
DRIVER DOOR AJAR
If the driver’s door is not fully closed, this message will
appear on the display and you will hear a chime.
Stop and turn off the vehicle, check the door for
obstacles, and close the door again. Check to see if the
message still appears on the DIC. Press the select
button to acknowledge this message and clear it from
the DIC display.
ENGINE COOLANT HOT/ENGINE
OVERHEATED
If the cooling system temperature gets hot, this message
will appear in the DIC and you will hear a chime. See
Engine Overheating on page 5-28for the proper course
of action. This message will clear when the coolant
temperature drops to a safe operating temperature.
Notice:If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If
an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. Do not increase the engine speed above
normal idling speed. SeeEngine Overheating on
page 5-28for more information.
3-56

Are there hidden surface obstacles? Ruts? Logs?
Boulders?
What is at the bottom of the hill? Is there
a hidden creek bank or even a river bottom
with large rocks?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a
low gear. This way, engine drag can help your brakes
and they will not have to do all the work. Descend
slowly, keeping your vehicle under control at all times.
{CAUTION:
Heavy braking when going down a hill can
cause your brakes to overheat and fade. This
could cause loss of control and a serious
accident. Apply the brakes lightly when
descending a hill and use a low gear to keep
vehicle speed under control.
Q:Are there some things I should not do when
driving down a hill?
A:Yes! These are important because if you ignore them
you could lose control and have a serious accident.
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too steep
to drive down may be too steep to drive across. You
could roll over if you do not drive straight down.
Never go downhill with the transmission in
NEUTRAL (N). This is called “free-wheeling.”
Your brakes will have to do all the work and
could overheat and fade.
Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going uphill.
But if it happens going downhill, here is what to do.
1. Stop your vehicle by applying the regular brakes.
Apply the parking brake.
2. Shift to PARK (P) and, while still braking, restart
the engine.
3. Shift back to a low gear, release the parking brake,
and drive straight down.
4. If the engine will not start, get out and get help.
4-25

Then, shut the engine off and close the window almost all
the way to preserve the heat. Start the engine again and
repeat this only when you feel really uncomfortable from
the cold. But do it as little as possible. Preserve the fuel
as long as you can. To help keep warm, you can get out
of the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If You Are Stuck: In Sand, Mud, Ice
or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you do not want to
spin your wheels too fast. The method known as rocking
can help you get out when you are stuck, but you
must use caution.
{CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured.
And, the transmission or other parts of the
vehicle can overheat. That could cause an
engine compartment re or other damage.
When you are stuck, spin the wheels as little as
possible. Do not spin the wheels above 35 mph
(55 km/h) as shown on the speedometer.
Notice:Spinning your wheels can destroy parts of
your vehicle as well as the tires. If you spin the
wheels too fast while shifting your transmission
back and forth, you can destroy your transmission.
For more information about using tire chains on your
vehicle, seeTire Chains on page 5-68.
4-43

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear, under heavy
loads or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar
to engine overheating. To avoid this, let the engine run
while parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few minutes
before turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 5-28.
4-65

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Oil Life System..................................5-19
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-28
Engine Overheating.......................................5-28
Cooling System............................................5-30Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-47
Four-Wheel Drive............................................5-48
Front Axle......................................................5-48
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps....................................5-50
Taillamps, Turn Signal, and Stoplamps............5-50
Back-Up Lamps............................................5-51
Replacement Bulbs.......................................5-51
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
Tire Sidewall Labelling...................................5-55
Tire Terminology and Denitions.....................5-58
Ination - Tire Pressure.................................5-61
Tire Inspection and Rotation...........................5-62
When It Is Time for New Tires.......................5-64
Section 5 Service and Appearance Care
5-1