2000 PONTIAC GRAND PRIX cooling

3-8
Heating
On cold days use LOWER. The system will bring in
outside air, heat it and send it to the floor ducts. Please
note that the windows may fog up when using this
setting in the RECIRC mode. See ªRecirculationº in the
Index for more information.
If your vehicle has an engine coolant heater, you can use
it to help your system provide warm air faster when it's
cold outside 0
F (
-18
C) or lower. An engine coolant
heater warms the coolant your engine and heating
system uses to provide heat. See ªEngine Coolant
Heaterº in the Index.
Ventilation
For mild, outside temperatures when little heating or
cooling is needed, use UPPER with the A/C button off,
to direct outside air through your vehicle. Your vehicle
also has the flow
-through ventilation system described
later in this section.
Defogging and Defrosting
Your system has two settings for clearing the front and
side windows. To defrost the windows quickly, use DEF.
To warm passengers while keeping the windows clean,
use DEFOG.
Rear Window Defogger
Your comfort control system has a button to operate
your rear window defogger. The electronic comfort
control system has a button marked REAR.
The system with automatic temperature control has a
button marked R.DEF.
The rear window defogger uses a warming grid to
remove fog from the rear window. Press the button to
turn the rear defogger on. It will turn itself off after
about ten minutes.
If you turn it on again, the rear defogger will only run
for about five minutes before turning off. You can also
turn it off by pressing the button again.

4-25
Hill 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. Shift to a lower gear when you go
down a steep or long hill.
CAUTION:
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.

4-40 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 transaxle fluid (don't overfill),
engine oil, drive belts, cooling system and brake system.
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 this information before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. See ªEngine Overheatingº
in the Index.

5-
5-1
Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-2 Other Warning Devices
5
-3 Jump Starting
5
-9 Towing Your Vehicle
5
-10 Engine Overheating5
-13 Cooling System
5
-23 If A Tire Goes Flat
5
-24 Changing a Flat Tire
5
-35 Compact Spare Tire
5
-36 If You're Stuck: in Sand, Mud, Ice or Snow

5-13
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
3100 V6 Engine
A. Electric Engine Cooling Fans
B. Radiator Pressure Cap
C. Coolant Recovery Tank
3800 V6 and 3800 V6 Supercharged Engines
A. Electric Engine Cooling Fans
B. Radiator Pressure Cap
C. Coolant Recovery Tank

5-14
CAUTION:
An electric engine cooling fan under the hood 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.
When the engine is cold, the coolant level should be at
or above the COLD mark on the coolant recovery tank.
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.

5-15
CAUTION:
Heater and radiator hoses, and 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.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added
to the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.
If there seems to be no leak, with the engine on, check to
see if the electric engine cooling fans are running. If the
engine is overheating, both fans should be running.
If they aren't, your vehicle needs service.

5-16 How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the COLD mark, add a 50/50 mixture of clean,
drinkable water and DEX
-COOL
engine coolant at the
coolant recovery tank. (See ªEngine Coolantº in the
Index for more information.)
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.