1998 GMC ENVOY Owners Manual

Driving in Water
Light rain causes no special off-road driving problems.
But heavy rain can mean flash flooding, and
flood
waters demand extreme caution.
Find
out how deep the water is before you drive through
it. If' it's deep enough to cover your wheel hubs. axles or
exhaust pipe, don't try it -- you probably won't get
through.
Also, water that deep can damage your axle
and other vehicle parts.
If the water isn't too deep, then drive through it slowly.
At fast 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
to stop.
' Driving through 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 vehicle over. Don't drive through rushing water.
See "Driving Through Wdter" in the Index for more
information
on driving through water.
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
da1nage. Also, check the fuel lines and cooling
system for any leakage.
4-26
ProCarManuals.com

Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
Drivin at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be
impaired
-- by alcohol or drugs, with night vision
problems. or by fatigue. Here
are some tips on night driving.
0 Drive defensively.
0 Don't drink and drive.
0 Adjust your inside rearview mirror to reduce the
0 Since you can't see as well, you may need to slow
c2 "lare from headlamps behind you.
down and keep more space between
you and
other vehicles.
0 Slow down, especially on higher speed roads. Your
headlamps can light up only
so much road ahead.
In remote areas, watch for animals.
If you're tired. pull off the road in a safe place
and rest.
Night Vision
No one can see as well at night as in the daytime. But as
we get older these differences increase.
A 50-year-old
driver may require at least twice as much light to
see the
same thing
at night as a 20-year-old.
What you do
in the daytime can also affect your night
vision. For example,
if you spend the day in bright
sunshine
you are wise to wear sunglasses. Your eyes will
have
less trouble adjusting to night. But if you're
driving,
don't wear sunglasses at night. They may cut
down on glare from headlamps, but they also make a lot
of things invisible.
4-27
I
ProCarManuals.com

You can be temporarily blinded by approaching
headlamps. It can take
a second or two, or even several
seconds,
for your eyes to readjust to the dark. When you
are faced with severe glare
(as from a driver who
doesn’t lower the high beams, or a vehicle with
misaimed headlamps), slow down a little. Avoid staring
directly into the approaching headlarnps.
Keep your windshield and all the
glass oi=ryour vehicle
clean
-- inside and out. Glare at night is made much
worse by dirt on the glass. Even the inside
of the glass
can build up
a film caused by dust. Dirty glass makes
lights dazzle and flash more than clean glass would,
making
the pupils of your eyes contract repeatedly.
Remember that your headlamps light
up far less of a
roadway when you are in a turn or curve. Keep your
eyes moving; that way, it’s easier to pick out dimly
lighted objects. Just
as your headlamps should be
checked regularly for proper
aim, so should your eyes
be examined regularly. Some drivers suffer from night
blindness
-- the inability to see in dim light -- and aren’t
even aware
of it.
Driving in Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you can‘t stop, accelerate or turn
as well because
your tire-to-road traction isn‘t as good
as on dry roads.
And,
if your tires don’t have much tread left, you’ll get
even
less traction. It’s always wise to go slower and be
cautious
if rain starts to fall while you are driving. The
surface may get wet suddenly when your reflexes are
tuned for driving
on dry pavement.
ProCarManuals.com

The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are
in good shape, a heavy rain
can make
it harder to see road signs and traffic signals,
pavement markings, the edge
of the road and even
people walking.
It’s wise to keep your wiping equipment in good shape
and keep your windshield washer tank filled
with
washer fluid. Replace your windshield wiper inserts
when they show signs
of streaking or missing areas on
the windshield, or when strips of rubber start
to separate
from
the inserts. Driving
too fast through large water puddles or even
going through some car washes can cause problems, too.
The water may affect your brakes. Try to avoid puddles.
But
if you can’t, try to slow down before you hit them.
Wet brakes can cause accidents. They won’t work
as well in a quick stop and may cause pulling to
one side. You could lose control
of the vehicle.
After driving through a large puddle
of water or
a car wash, apply your brake pedal lightly until
your brakes work normally.
ProCarManuals.com

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 fdst rule about hydroplaning. The
best advice
is to slow down when it is raining.
1 )riving Through Deep Standing W ’ Fr
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.
Some Other Rainy Weather Tips
0 Besides slowing down, allow some extra following
distance.
And be especially carefir1 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”
in the Index.)
4-30
ProCarManuals.com

City Driving One of the biggest problems with city streets is the
amount of traffic on them.
You'll want to watch out for
what the other drivers are doing and pay attention to
traffic signals.
Here are ways to increase your safety
in city driving:
0 Know the best way to get to where you are going. Get
a city map and plan your trip into an unknown part of
the city just as you would for a cross-country trip.
0 Try to use the freeways that rim and crisscross most
large cities. You'll save time and energy. (See the
next part, "Freeway Driving.")
0 Treat a green light as a warning signal. A traffic light
is there because the corner
is busy enough to need it.
When a light turns green, and just before you start to
move, check both ways for vehicles that have not
cleared the intersection or may be running the
red light.
4-3 1
I
ProCarManuals.com

Freeway Driving
Mile for mile, freeways (also called thruways, parkways,
expressways, turnpikes or superhighways) are the safest
of all roads. But they have their own special rules.
The most important advice
on freeway driving is: Keep
up with traffic and keep to the right. Drive at the same
speed most of the other drivers are driving. Too-fast
or
too-slow driving breaks a smooth traffic flow. Treat the
left lane on a freeway as a passing lane.
At the entrance, there is usually a ramp that leads to the
freeway.
If you have a clear view of the freeway as you
drive along the entrance ramp, you should begin to
check traffic. Try to determine where you expect to
blend with the flow. Try to merge into the gap at close to
the prevailing speed. Switch
on your turn signal, check
your mirrors and glance over your shoulder as often as
necessary. Try to blend smoothly
with the traffic flow.
Once you are on the freeway, adjust your speed
to the
posted limit or to the prevailing rate if it’s slower. Stay
in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before
you leave the lane, glance quickly over your
shoulder
to make sure there isn’t another vehicle in your
“blind” spot.
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.
4-32
ProCarManuals.com

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 GM
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:
0
0
0
0
0
0
0
WincJsl~ield Wcrshc~r- Fluid: Is the reservoir full? Are
all windows clean inside and outside?
Wiper Blcrdes: Are they in good shape?
Fuel, Elzgirze Oil, Other Flr.ds: Have you checked
all levels‘?
Lcunps: 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 drivingi? Are the tires all inflated
to the
recommended pressure?
Wecrther Forec*cr.sts: What’s the weather outlook
along your route? Should
you delay your trip a short
time to avoid
a major storm system?
A4crp.s: Do you have up-to-date maps?
4-33
I
ProCarManuals.com