2003 PONTIAC GRAND PRIX radiator

Radiator Pressure Cap
Notice: Your radiator cap is a pressure-type cap
and must be tightly installed to prevent coolant
loss
and possible engine damage from overheating.
Be sure the arrows on the cap line up with the
overflow tube
on the radiator filler neck.
The radiator pressure cap is located in the front of the
engine compartment on the passenger’s side, near
the diagonal cross brace. See Engine Compartment
Overview on page
5-12 for more information on location.
Engine Overheating
You will find a coolant temperature gage and a warning
light concerning an overheated engine condition on
the instrument panel cluster. See Engine Coolant
Temperature Gage
on page 3-31 and Engine Coolant
Temperature Warning Light
on page 3-31.
Overheated Engine Protection
Operating Mode
This emergency operating mode allows your vehicle to
be driven tu
a safe place in an emergency situation.
If an overheated engine condition exists, an overheat
protection mode which alternates firing groups of
cylinders helps prevent engine damage. In this mode,
you will notice a significant
loss in power and engine
performance. The engine coolant temperature gage will
indicate an overheat condition exists. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
Nofice: After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant
loss, change the oil
and reset the oil life system. See “Engine Oil”
ir
the Index.
5-33

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
I
3100 V6 Engine
A. Coolant Recovery Tank
B. Electric Engine Cooling Fans
C. Radiator Pressure Cap
5-36

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 vehicle
should be parked on a level surface. 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 at the pressure cap or in
the radiator hoses, heater hoses, radiator, water
pump or somewhere else in the cooling system.
5-37

He !r : I r8 r hoses, ar 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.
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.
Notice: Engine damage from running your engine
without coolant isn’t covered by your warranty. See “Overheated Engine Protection Operating
Mode’’
in the Index for information on driving to a
safe place
in an emergency.
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.
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
Engine Coolant on
page 5-30 for more information.
5-38

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. Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as 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.
You car.
._e burnec. .. you spi-. :oolant 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.
When the coolant in the coolant recovery tank
is at the
COLD mark, start your vehicle.
5-39

If the overheat warning continues, there’s one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
Steam and scalding liquids from a hot cooling
~
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator pressure cap
-- even a little -- they can come
out at high speed. Never turn the 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.
5-40

40w to Add Coolant to the Radiator The radiator pressure cap is located on the passenger’s
side of the vehicle
in the front of the engine
dotice: Your engine has a specific radiator compartment, near the battery and the diagonal cross
ill procedure. Failure to follow this procedure could brace. See Engine Compartment Overview on page 5-12
:ause your engine to overheat and be severely for more information on location.
lamaged. You can remove the radiator pressure cap when the
cooling system, including the radiator pressure cap and
upper radiator hose, is no longer hot.
1. Turn the pressure cap slowly counterclockwise 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.
5-4 1

3800 V6 engine: There is
one bleed valve. It is
located on the thermostat
housing.
Thermostat Housing
(3800 V6)
5. Fill the radiator with the proper DEX-COOL@
coolant mixture, up to the base of the filler
neck. See Engine Coolant
on page 5-30 for more
information about the proper coolant mixture.
If you see a stream of coolant coming from an air
bleed valve, close the valve. Otherwise, close
the valves after the radiator is filled.
6. Rinse or wipe any spilled coolant from the engine
and the compartment.
7.
If you have the 3800 V6 engine, replace the 3800
7.1. Remove the oil fill tube, with cap attached,
Series
II V6
engine cover shield.
from the valve cover.
7.2. Insert the catch tab on the cover shield
under the bracket
on the engine.
7.3. Place the hole in the cover shield over the
hole
in the valve cover. Install oil fill tube and
cap by twisting clockwise.
7.4. If you have the supercharged engine, install
the nut in the center
of the cover shield.
5-44