1998 GMC SIERRA cooling

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. See
“Brake System Warning Light” earlier
in this section.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn‘t come on then. have it fixed
so it will be
ready to warn you
if there is a problem.
Engine Coolant Temperature Gage
1
This gage shows the engine
coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read
210°F (100°C) or less. If you are pulling a
load or going up hills, it is normal for the temperature to
fluctuate and approach the
260°F (1 25 “C) mark. If the
gage reaches the
260°F (125°C) mark, it indicates that
the cooling system is working beyond its capacity.
The “Problems on
the Road,” section of this manual shows
what
to do. See “Engine Overheating” in the Index.
Malfunction Indicator Lamp (Service
Engine
Soon Light) (Gasoline Engine)
SERVICE
ENGINE
SOON
Your vehicle is equipped
with a computer which
monitors operation
of the
fuel, ignition and emission
control systems.
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Mode Knob
The right knob on the control panel allows you to
choose the direction
of air delivery. The control knob
can be placed in any position between two mode settings
to blend the flow of air.
+e
/$ VENT This setting directs air through the
instrument panel outlets.
+’ VENT/HEAT Use this setting to divide airflow
between the floor outlets and instrument panel outlets.
+’ HEATER: This setting directs air through the
+e
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heater floor outlets.
+’ DEFOG: This setting directs air to the heater
we
outlets and toward the windshield.
DEFROST This setting directs air toward the
windshield.
Air Conditioning
On hot days, open the windows long enough to let hot
air inside escape. This reduces the titne
it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best. The recirculation button, between the
fan and
temperature
knobs, allows the air inside your vehicle to
be recirculated. This setting helps to maximize your air
conditioner’s performance and your vehicle’s fuel
economy. This setting also cools the air the fatest and
can be used
to keep unwanted odors and/or dust from
entering the vehicle. When using the air conditioner,
turn off recirculation after the vehicle reaches
a
comfortable interior temperature. When the right knob
on the control panel is between HEATER and
DEFROST, the recirculation feature will not function.
The A/C button, between the temperature and mode
knobs, allows the air coming into your vehicle to be
cooled. This setting is useful for normal cooling on hot
days. When you use
A/C with the recirculation button
pushed
in, turn off recirculation as soon as the vehicle
reaches
a comfortable interior temperature.
With the A/C
on, move the temperature knob to MAX
for maximum cooling. This setting also puts the system
in the recirculation mode and helps to maximize your air
conditioner‘s performance and your vehicle’s fuel
economy. This setting also cools the air the Fdstest. After
the vehicle‘s interior reaches
a comfortable temperature,
move the temperature knob to the right, to place the air
conditioning system
in the normal mode.
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Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the
HEATER or
VENTMEAT setting with the temperature knob in the
red area.
If you use the engine coolant heater before starting your
engine in cold weather,
20” F (-8 O C) or lower, your
heating system will produce warmer air faster, to heat
the passenger compartment
in cold weather.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature, and shortens the time it takes the heater to
reach full output. For more information, see “Engine
Coolant Heater” in the Index.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed,
use VENT to direct outside air
through your vehicle. Air will flow through the
instrument panel outlets.
Your vehicle’s ventilation system supplies outside
air to
the inside of your vehicle when
it is moving. With the side
windows closed,
air will flow into the front air inlet grilles,
through the vehicle, and out the
air exhaust valves. Outside air
will also enter the vehicle when the heater or
the air conditioning fan is running, unless you have the
recirculation button pushed in. For more information on
the recirculation button, see “Air Conditioning’’ earlier
in this section.
Your vehicle has air outlets in the center and
on the sides
of your instrument panel. You can move the outlets from
side-to-side or up and down to direct the flow of air, or
close the outlets altogether. When you close an outlet,
it
will increase the flow of air coming out of any outlets
that are open. These outlets do not completely shut off
airflow when in the closed position.
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steering, suspension, wheels, tires ana exhaust system
for damage.
Also, check the fuel lines and cooling
system for any leakage. 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.
Your vehicle will require more frequent service due to
off-road use. Refer
to the Maintenance Schedule for
additional information.
Driving at Night
Here are some tips on night driving.
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Drive defensively.
Don’t drink and drive.
Adjust your inside rearview mirror
to reauce me
glare from headlamps behind you.
Since you can’t see as well,
you may need to
slow down and keep more space between you and
other vehicles.
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.
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Keep your vehicle in good shape. Check all fluid
levels and also the brakes, tires, cooling system and
transmission. These parts can work hard on
mountain roads.
Know how to go down hills. The most important
thing to know
is this: let your engine do some of the
slowing down. Shift to
a lower gear when you go
down a steep or long hill.
I A CAJTION: I
If you don’t shift down, your brakes could get so
hot that they wouldn’t work well. You would then
have poor braking or even none going down
a hill.
You could crash. Shift down to let your engine
assist your brakes on a steep downhill slope. Coasung
aownhill in NEUTRAL
(N) or with the
ignition
off is dangerous. Your brakes will have
to do all the work
of slowing down. They could
get
so hot that they wouldn’t work well. You
would then have poor braking or even none going
down
a hill. You could crash. Always have your
engine running and your vehicle in gear when
you go downhill.
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Know how ro g6 uphill. You may want to shift down
to a lower gear.
The lower gears help cool your engine
and transmission, and you can climb the hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Don’t swing wide or cut
across the center
of the road. Drive at speeds that let
you stay in your own lane.
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0 As you go over the top of a hill, be alert. There could be
something in your lane, like a stalled car
or an accident.
You may see highway signs
on mountains that warn of
special problems. Examples are long grades, passing or
no-passing zones, a falling rocks area or winding
roads. Be alert
to these and take appropriate action.
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5. If you have a four-wheel-drive vehicle,
be sure the transfer case is in
a drive gear and not
in
NEUTRAL (N).
6. Release the regular brakes.
-
/r CAUTIOIA:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in
PARK (P) with the
parking brake firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured.
To be sure your vehicle won’t move, even
when you’re on fairly level ground, use the steps
that follow.
If you have four-wheel drive and your transfer
case is in
NEUTRAL (N), your vehicle will be free
to
roll, even if your shift lever is in PARK (P). So,
be sure the transfer case is in a drive gear -- not
in
NEUTRAL (N).
When You Are Ready to Leave After
Parking
on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine;
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly
until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling
a trailer. See the Maintenance Schedule for more
on this. Things that are especially important
in trailer
operation are automatic transmission fluid (don’t
overfill), engine
oil, axle lubricant, belt, cooling system
and brake adjustment. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before
you start your trip.
Check periodically
to see that all hitch nuts and bolts
are tight.
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SI ;tion 5 Problems on the Road
Here you’ll find what to do about some problems that can occur on the road.
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5-3
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5-8
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Hazard Warning Flashers
Other Warning Devices
Jump Starting
Towing Your Vehicle
Engine Overheating (Gasoline Engine) 5- 15
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5-23
5-24
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Cooling System -- Gasoline Engines
Engine Fan Noise
If a Tire Goes Flat
Changing a
Flat Tire
If You’re Stuck: In Sand, Mud, Ice or Snow
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If you get the overheat warning with no sign of steam,
try this for
a minute or so:
1. If you have an air conditioner, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window
as necessary.
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (@)
for automatic transmissions.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about
10 minutes.
If the warning doesn’t come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign
of steam, push the accelerator until
the engine speed
is about twice as fdst as normal idle
speed. Bring the engine speed back to normal idle speed
after two or three minutes. Now see if the warning stops.
But then, if you still have the warning, turn ofthe
engine
and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
Cooling System -- Gasoline Engines
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan(s)
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