2003 GMC SIERRA DENALI engine

Getting Familiar with Off-Road Driving
It’s a good idea to practice in an area that’s safe and
close to home before you go into the wilderness.
Off-road driving does require some new and different
driving skills. Heres’s what we mean.
Tune your senses to different kinds of signals. Your
eyes, for example, need to constantly sweep the terrain
for unexpected obstacles. Your ears need to listen
for unusual tire or engine sounds. With your arms,
hands, feet and body, you’ll need to respond to
vibrations and vehicle bounce.
Controlling your vehicle is the key to successful off-road
driving. One of the best ways to control your vehicles
is to control your speed. Here are some things to keep in
mind. At higher speeds:
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you approach things faster and you have less time
to scan the terrain for obstacles.
you have less time to react.
you have more vehicle bounce when you drive over
obstacles.
you’ll need more distance for braking, especially
since you’re on an unpaved surface. When you’re driving off-road,
bouncing and
quick changes in direction can easily throw
you out of position. This could cause you to
lose control and crash.
So, whether you’re
driving on or
off the road, you and your
passengers should wear safety belts.
Scanning the Terrain
Off-road driving can take you over many different kinds
of terrain. You need to be familiar with the terrain
and its many different features. Here are some things to
consider.
Surface Conditions: Off-roading can take you over
hard-packed dirt, gravel, rocks, grass, sand, mud, snow
or ice. Each of these surfaces affects the steering,
acceleration and braking of your vehicle in different
ways. Depending upon the kind of surface you are on,
you may experience slipping, sliding, wheel spinning,
delayed acceleration, poor traction and longer braking
distances.
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Q: What should I do if my vehicle stalls, or is
A: if this happens, there are some things you should
about to stall, and
I can’t
make it up the hill?
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do and there are some things you must not do.
First, here’s what you should do:
Push the brake pedal to stop the vehicle and keep
if from rolling backwards. Also, apply the parking
brake.
If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill as straight as possible in
REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the
12 o’clock position.
This way, you’ll be able to tell
if your wheels
are straight and maneuver as you back down. It’s
best that you back down the hill with our wheels
straight rather than in the left or tight direction.
Turning the wheel too far to the left
or right
will increase the possibility of a rollover. Here are
some things you
must not do if you stall, or
are about to stall, when going up a
hill.
9 Never attempt to prevent a stall by shifting into
NEUTRAL
(N) to “rev-up” the engine and regain
forward momentum. This won’t work. Your vehicle
will roll backwards very quickly and you could
go out of control.
Instead, apply the regular brake to stop the vehicle.
Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and
slowly back straight down.
9 Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep
enough to stall your vehicle, it’s steep enough to
cause you to roll over
if you turn around. If you can’t
make it up the hill, you must back straight down
the hill.
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Q: Suppose, after stalling, I try to back down the hill
A: Set the parking brake, put your transmission in
PARK (P) and turn
off the engine. Leave the
vehicle and go get some help. Exit
on the uphill
side and stay clear of the path the vehicle would
take
if it rolled downhill.
and decide
I just can’t
do it. What should I do?
Driving Downhill
When off-roading takes you downhill, you’ll want to
consider a number of things:
How steep is the downhill? Will I be able to maintain
vehicle control?
What’s the surface like? Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
0 Are there hidden surface obstacles? Ruts? Logs?
What’s at the bottom of the hill? Is there a hidden
Boulders?
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 won’t hate to do all the work. Descend slowly,
keeping your vehicle under control at all times. Heavy
braking when going down a
h 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
A: Yes! These are important because if you ignore
driving
down a hill?
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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’s not too
steep to drive down may be too steep to drive
across. You could roll over
if you don’t 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.
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Q: Am I likely to stall when going downhill?
A: It’s much more likely to happen going uphill. But if it
* Stop your vehicle by applying the regular brakes.
happens
going downhill, here’s what to do.
Apply the parking brake.
Shift to PARK (P) and, while still braking, restart the
Shift back to a low gear, release the parking brake,
engine.
and
drive straight down.
0 If the engine won’t start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline of a hill. If this happens, you have to
decide whether to try to drive across the incline. Here
are some things to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up or
down a hill, the length of the wheel bas (the distance
from the front wheels to the rear wheels) reduces the
likelihood the vehicle will tumble end over end. But
when you drive across an incline, the much more
narrow track width (the distance between the left and
right wheels) may not prevent the vehicle from tilting
and rolling over. Also, driving across an incline puts
more wight on the downhill wheels. This could cause
a downhill slide or a rollover.
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Surface conditions can be a problem when you drive
across a hill. Loose gravel, muddy spots, or even wet
grass can cause your tires to slip sideways, downhill.
If the vehicle slips sideways, it can hit something that
will trip it (a rock,
a rut, etc.) and roll over.
Hidden obstacles can make the steepness of the
incline even worse.
If you drive across a rock with the
uphill wheels, or
if the downhill wheels drop into a rut
or depression, your vehicle can tilt even more.
For reasons like these, you need to decide carefully
whether to try to drive across an incline. Just because the
trail goes across the incline doesn’t mean you hat to drive
it. The last vehicle to try it might have rolled over.
Driving across an incline that’s too steep will
make your vehicle roll over. You could be
seriously injured or killed.
If you have any
doubt about the steepness
of the incline, don’t
drive across it. Find another route instead.
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If the water isn’t too deep, drive slowly through it. At
faster speeds, water splashes on your ignition system
and your vehicle can stall. Stalling can also occur
if you
get your tailpipe under water. And, as long as your
tailpipe is under water, you’ll never be able to start your
engine. When you go through water, remember that
when your brakes get wet, it may take you longer
+- stop.
,,jving thr,,gh rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it’s only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
water.
~ vehicle over. Don’t drive through rushing
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After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a fire hazard.
After operation
in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due
to
off-road use. Refer to the Maintenance Schedule
for additional information.
See
Driving in Rain and on Wet Roads on page 4-30 for
more information on driving through water.
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Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen
if the road is wet enough and
you’re going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning doesn’t happen often. But it can
if
your tires do not have much tread or if the pressure in
one or more is low. It can happen
if a lot of water is
standing on the road. If you can see reflections
from trees, telephone poles or other vehicles, and
raindrops “dimple” the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds. There
just isn’t a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice: If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage your engine. Never drive through water that is
slightly lower than the underbody
of your vehicle. If
you can’t avoid deep puddles or standing water,
drive through them very slowly.
Driving Through Flowhg W=+er
--m
Flowing or rushing water creates strong forces.
If you try to drive through flowing water, as you
might at a low water crossing, your vehicle can
be carried away.
As little as six inches of
flowing water can carry away
a smaller vehicle.
If this happens, you and other vehicle
occupants could drown. Don’t ignore police
warning signs, and otherwise be very cautious
about trying to drive through flowing water.
Some Other Rainy Weather Tips
Turn on your low-beam headlamps - not just your
parking lamps
- to help make you more visible to
others.
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
Have good tires with proper tread depth. See
Tires
on page 5-6 I.
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Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to
move slightly slower at night.
When you want
to leave the freeway, move to the
proper lane well in advance.
If you miss your exit, do
not, under any circumstances, stop and back up. Drive
on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend
to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh
- such as after a day’s
work
- don’t plan to make too many miles that first
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it’s ready to go. If it needs
service, have it done before starting out.
Of course,
you’ll find experienced and able service experts
in dealerships all across North America. They’ll be
ready and willing to help
if you need it.
Here are some things you can check before a trip:
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Windshield Washer Fluid: Is the reservior full? Are
all windows clean inside and outside?
Wiper Blades: Are they in good shape?
Fuel, Engine Oil, Other Fluids: Have you checked
all levels?
Lamps: Are they all working? Are the lenses clean?
Tires: They are vitally important to a safe,
trouble-free trip.
Is the tread good enough for
long-distance driving? Are the tires all inflated to the
recommended pressure?
Weather Forecasts: What’s the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps: Do you have up-to-date maps?
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Highway Hypnosis
Is there actually such a condition as "highway
hypnosis"? Or is it just plain falling asleep at the wheel?
Call it highway hypnosis, lack of awareness, or
whatever.
There is something about an easy stretch of road with
the same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush
of the
wind against the vehicle that can make you sleepy. Don't
let it happen to you!
If it does, your vehicle can leave
the road in
less than a second, and you could crash and
be injured.
What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with a
Keep your eyes moving. Scan the road ahead and
comfortably cool interior.
to the
sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in flat
or rolling terrain.
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