open hood GMC ENVOY DENALI 2008 Owners Manual

Adjustable Throttle and Brake Pedal
If your vehicle has this feature, you can change the
position of the throttle and brake pedals. This feature is
designed for shorter drivers, since the pedals cannot
move farther away from the standard position, but can
move closer for better pedal reach.
The vehicle must be in PARK (P) for this feature to
operate.
The switch used to adjust
the pedals is located on
the steering column.
Press the switch forward or backward to move the
pedals closer or farther away from you.
Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
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 next to the battery box
facing the engine.
3. Plug it into a normal, grounded 110-Volt AC outlet.
2-24

Outlet Adjustment
Use the air outlets located in the center and on the
side of the instrument panel to direct the airow. Use
the thumbwheels near the air outlets to open or close
off the airow.
Operation Tips

Clear away any ice, snow, or leaves from air inlets
at the base of the windshield that could block the
ow of air into the vehicle.
Keep the path under the front seats clear of objects
to help circulate the air inside of the vehicle more
effectively.
Use of non-GM approved hood deectors can
adversely affect the performance of the system.
Check with your dealer/retailer before adding
equipment to the outside of your vehicle.
Rear Climate Control System
Your vehicle has one of the following rear climate
control systems. With either of these systems, the
rear climate controls will be disabled when the front
climate control system is in defrost. This occurs to
provide maximum airow to clear the windshield.The temperature of the air coming through the rear
outlets is determined by the front passenger temperature
setting. Use the mode knob to change the direction of
airow (upper, bi-level or oor) to the rear seat area.
PWR (Power):Press this button to turn the rear climate
controls on or off.
H(Panel):This position distributes air from the rear
console outlets.
)(Bi-level):This position distributes air from the
second seat side oor outlets and the rear console
outlets.
6(Floor):This position distributes air from the
second seat side oor outlets.
3-28

Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511
in Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7for
additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-41. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by your warranty.
5-6

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the fuel vapor. You
can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
Dispense fuel only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed, or
on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer and
other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

Hood Release
1. To open the hood, rst
pull the handle with this
symbol on it. It is
located inside the
vehicle under the
instrument panel on the
driver’s side.
2. Then go to the front of the vehicle and release the
secondary hood release.
3. Lift the hood, release the prop rod from its retainer
and put the prop rod into the slot in the hood.
Before closing the hood, be sure all the ller caps are
on properly. Then lift the hood to relieve pressure on the
prop rod. Remove the prop rod from its slot in the hood
and return the prop to its retainer. Lower the hood
6 to 8 inches (15 to 20 cm) above the vehicle and release
it to latch fully. Check to make sure the hood is closed
and repeat the process if necessary.
5-11

Engine Compartment Overview
When you open the hood on the 4.2L L6 engine, here is what you will see:
5-12

When you open the hood on the 5.3L V8 engine, here is what you will see:
5-14

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.
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.
5-29

Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered by
your warranty. Always turn off your radio and other
accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets, if equipped.
Turn off the radio and all lamps that are not
needed. This will avoid sparks and help to save
both batteries. And it could save the radio!
4. Open both hoods and locate the batteries. Find the
positive (+) and negative (−) terminals on each
battery. Your vehicle has a remote negative (−) jump
starting terminal. You should always use this
remote terminal instead of the terminal on the
battery. The remote negative (−) terminal is located
on the front engine lift bracket on vehicles with the
4.2L L6 engine or the engine accessory drive bracket
for vehicles with the 5.3L V8 engine, and is marked
GND (Ground). SeeEngine Compartment Overview
on page 5-12for more information on location.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
ashlight if you need more light.
Be sure the battery has enough water. You do
not need to add water to the battery installed
in your new vehicle. But if a battery has ller
caps, be sure the right amount of uid is there.
If it is low, add water to take care of that rst.
If you do not, explosive gas could be present.
Battery uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ush the place
with water and get medical help immediately.
5-43

Headlamps
To replace one of these bulbs:
1. Open the hood.Hood Release on page 5-11for
more information.
2. Lift the two headlamp retaining clips.
3. Pull the headlamp assembly away from the vehicle
to access the electrical connectors.4. Remove the cover from the headlamp bulb.
5. Remove the bulb socket that needs to be replaced
by turning it counterclockwise.
6. Disconnect the electrical connector from the
old bulb.
7. Plug the electrical connector into the new bulb
using care not to touch the glass with your
ngers.
8. Install the new bulb into the socket and turn it
clockwise to secure.
9. Reinstall by reversing Steps 1 through 6.
10. Press down on the headlamp retaining clips to
secure the headlamp assembly.
5-50