1993 PONTIAC BONNEVILLE cooling

Engine Coolant Temperature Warning Light
This light tells you that your engine
coolant has overheated
or your radiator
cooling fans are
not working. If you
have been operating your vehicle under
normal driving conditions, you should
pull off the road, stop your vehicle and
turn the engine
off as soon as possible.
HOT
COOLANT CAN BURN YOU
BADLY!
In Problems on the Road, this
manual shows what to do. See the
Index
under Engine Overheating.
Some clusters with gages do not have a
coolant temperature warning light.
In
those clusters a CHECK GAGES
warning light will alert you of a
potential coolant heating problem.
Low Coolant Warning light
(OPT/ON)
If this light comes on, your system may
be low
on coolant and the engine may
overheat. Check to see
if the level is
low, and add coolant if necessary. See
the
Index under Engine Coolant.
The LOW COOLANT warning light
will also come on when
you turn on the
ignition, but your engine is not running,
as a check to show you it is working.
If
it doesn’t come on then, have it fixed
right away.
101
ProCarManuals.com

Comfort Controls & Audio Systems ~ ~~
I
Standard Climate Control
The air conditioner and heater work
best
if you keep your windows closed
while using them.
e : Selects the force of air you want.
The fan is always running unless the
mode control
is moved to OFF.
Temperature Control: The center
control regulates the temperature
of the
air coming through the system.
Mode Control: The right control has
settings for air conditioning and non-air
conditioning modes.
120
Air Conditioning Settings
There are three air conditioning settings.
On very hot days, open the windows
long enough to let hot inside air escape.
This reduces the time your air
conditioner's compressor
will have to
run, which should help fuel economy.
MAX: Provides maximum cooling or
quick cool-down on very hot days. This
setting recirculates much
of the air
inside your vehicle, and it should not be
used for long periods because
the air
may become too cold and dry.
A/C: Use for normal cooling on hot
days. This setting cools outside air and
directs it through the instrument panel
outlets.
I 9 (Bi-Level): Use on cool, but
sunny days. This setting brings
in the
outside air, but directs
it in two ways.
The cool air
is directed to the upper
portion
of your body through the
instrument panel outlets, but warmed air
1
is directed through the heater ducts and ~
defroster vents. At times this
temperature difference may be more
apparent than others.
The air conditioner compressor operates
in all air conditioner positions, and in
(@ (Defrost) and ,> (Defog) when
the outside temperature is above 50°F
(IOOC). When the air conditioner is on,
you may sometimes notice slight
changes
in your vehicle's engine speed
and power. This is normal, because the system
is designed to cycle the
compressor on and off to keep the
desired cooling and help fuel economy.
I
c ProCarManuals.com

., . .. -.
Electronic Climate Control
(OPTION)
With this system, you can control the
ventilation, heating and air conditioning
in your vehicle, or you can use the auto-
matic setting.
The digital screen displays the outside
temperature, the inside temperature setting, the fan speed, and the heating
mode you have selected.
The air conditioner compressor operates
in all
AUTO setting positions, and in
(@ when the outside temperature is
above 49°F (9°C). When the air
conditioner is on, you may sometimes
notice slight changes
in your vehicle's
engine speed and power. This is normal,
because the system
is designed to cycle
the compressor on and off to keep the
desired cooling and help
fuel economy.
TEMP: Sets the interior temperature
you want. The temperature you set will
be displayed on the digital screen.
Once you set the temperature, the system
will
try to maintain the set tempera-
ture, whether or not you are using the
heating or cooling controls. But
if you
set the temperature for 60°F (16°C) or
90"
F (32" C), the fan will stay on HI
speed unless you select a different
speed.
AUTO: To allow the system to
automatically control the temperature,
air distribution and fan speed:
1. Set the temperature you want with the
2. Press the AUTO switch.
TEMP switch.
EXT. TEMP: Press to have the outside
temperature displayed on the digital
screen (unless the system is
off). Press
again to return to the inside temperature
setting. When the system is
off, the
outside temperature will be displayed.
Use the following controls when
AUTO
is not desired.
% : Sets the fan speed. Press the top
of the switch to raise the fan speed, the
bottom of the switch to lower the fan
speed.
123 ' '
ProCarManuals.com

Your Driving and the Road
Hi// and Mountain Roads
Driving on steep hills or mountains is
different from driving
in flat or rolling
terrain.
If you drive regularly in steep
country, or if you’re planning to visit
there, here are some tips that can make
your trips safer and more enjoyable.
Keep your vehicle in good shape.
Check all fluid levels and also the
brakes, tires, cooling system and
transaxle. 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. Don’t make your brakes do
it
all. Shift to a lower gear when you go
down a steep or long hill. That way,
you will slow down without excessive
use of your brakes.
176
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.
I CAUTION I
Know how to go uphill. Shift down to
D (Drive). This will help cool your
engine and transaxle, 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. That
way, you won’t be surprised by a
vehicle coming toward you
in the
same lane.
It takes longer to pass another vehicle
when you’re going uphill. You’ll want
to leave extra room to pass.
If a
vehicle
is passing you and doesn’t have
enough room, slow down to make
it
easier for the other vehicle to get by.
ProCarManuals.com

Your Driving and the Road
Maintenance When Tmiler 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 transaxle fluid (don’t overfill),
engine oil, belts, 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.
... 190
ProCarManuals.com

Problems on the Road
Engine Overheating (CONK)
Cooling System
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) Electric engine fan
An
electric fan under the hood
h can start up even when the
engine is not running and can
injure
you. Keep hands, clothing
and tools away from any
underhood electric fan.
If the coolant inside the coolant
recovery tank is boiling, don’t do
anything else
until it cools down.
The coolant level should be at or above
the
FULL COLD mark. If it isn’t, you
may have a leak
in the radiator hoses,
heater hoses, radiator, water pump or
somewhere else
in the cooling system.
I I 1 Heater and radiator hoses, anc
- other engine parts, can be
very hot. Don’t touch them.
If you
do, you can be burned.
Don’t run the engine if there is a
leak.
If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you could
be burned. Get any leak fixed
before you drive the vehicle.
I
Engine damage from running your
engine without coolant isn’t
covered by your warranty.
.. . 204
ProCarManuals.com

should be running. If it isn’t, your
vehicle needs service.
How
to Add Coolant to the Coolant
Recovery Tank:
If you haven’t found a problem yet, but
the coolant level isn’t up to the
FULL
COLD mark, add a 50/50 mixture of
clean water (preferably distilled) and a
proper antifreeze at the coolant recovery
tank. See the Index under Coolant for
more information about the proper
coolant mix.
I b-Au I IUN If there seems to be no leak, check to
see
if the electric engine fan is running. Adding only plain water to
If the engine is overheating, the fan L your cooling system can be
dangerous. Plain water, or some
other liquid like alcohol, can boil
before the proper coolant
mix will.
Your vehicle’s coolant
warning
,k L
You can be burned if you spill
coolant on
hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are
hot enough. Don’t spill coolant
on a hot engine.
system is set for the proper coolant
I
mix. With plain water or the
too hot but you wouldn’t get the
overheat warning. Your engine
could catch fm and you or others
be Use a mix
of clean water and a proper
antifreeze. When
the coolant in the coolant
COLD, start your vehicle. If the
overheat warning continues, there’s one
proper coolant mix directly
to the
more
thing you can try. You can add the
radiator, but be sure the cooling system
is cool before
you do it.
wrong
mix, Your
engine could get recovery tank is at or above FULL
I
In cold weather, water can freeze II
and crack the engine, radiator,
heater core and other
parts. Use
the recommended coolant.
I
r
205 ”
ProCarManuals.com

Problems on the Road
i '. 'k
I Engine Overheating (CONT.)
Steam and scalding liquids
From a hot cooling system can
3w out and burn you badly. They
ale under pressure, and if you turn
I thl= radiator pressure cap-even a
tle-they can come out at high
I eed. Never turn the pressure cap
when the cooling system, including
the radiator pressure cap,
is hot.
Wait for the cooling system and
radiator pressure cap to cool if you
ever have to turn. the pressure cap.
How to Add Coolant to the Radiator:
1. You can remove the radiator pressure
cap when the cooling system,
including the radiator pressure cap
and upper radiator hose, is no longer
hot. Turn the pressure cap slowly to
the left
until it first stops. (Don't
press down while turning the
pressure cap.)
If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure
left.
2. Then keep turning the pressure cap,
but now push down as you turn it.
Remove the pressure cap.
ProCarManuals.com