2002 PONTIAC GRAND PRIX Owners Manual

5-17
CAUTION:
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.
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.
CAUTION:
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.

5-18
When the coolant in the coolant recovery tank is at the
COLD mark, start your vehicle.
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.
CAUTION:
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 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.

5-19 How to Add Coolant to the Radiator
NOTICE:
Your engine has a specific radiator fill procedure.
Failure to follow this procedure could cause your
engine to overheat and be severely damaged.
The radiator pressure cap is located on the passenger's side
of the vehicle in the front of the engine compartment, near
the battery and the diagonal cross brace. See ªEngine
Compartment Overviewº in the Index for more
information on location.
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.

5-20
2. Then keep turning the pressure cap, but now push
down as you turn it. Remove the pressure cap.
CAUTION:
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.
3. If you have the 3800 V6 engine, remove the
3800 Series II V6 engine cover shield to access
the bleed valve.

5-21
A. Clean the area around the engine oil fill tube and cap
before removing. Twist the oil fill tube, with cap
attached, counterclockwise and remove it.
B. If you have the supercharged engine, remove the nut
in the center of the cover shield.
C. Lift the engine cover shield at the front, slide the
catch tab out of the engine bracket and remove the
cover shield.
D. Put the oil fill tube, with cap attached, in the valve
cover oil fill hole until you're ready to replace the
cover shield.4. After the engine cools, open the coolant air bleed
valve or valves.Thermostat Housing
(3100 V6)Thermostat Bypass
Tube (3100 V6)
3100 V6 engine: There are two bleed valves. One is
located on the thermostat housing. The other is
located on the thermostat bypass tube.

5-22
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
ªEngine Coolantº in the Index 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.

5-23
6. Rinse or wipe any spilled coolant from the engine
and the compartment.
7. If you have the 3800 V6 engine, replace the
3800 Series II V6 engine cover shield.
A. Remove the oil fill tube, with cap attached, from
the valve cover.
B. Insert the catch tab on the cover shield under the
bracket on the engine.
C. Place the hole in the cover shield over the hole in
the valve cover. Install oil fill tube and cap by
twisting clockwise.
D. If you have the supercharged engine, install the
nut in the center of the cover shield.
8. Then fill the coolant recovery tank to COLD mark.
9. Put the cap back on the coolant recovery tank, but
leave the pressure cap off.

5-24
10. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.
11. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX
-COOL
coolant mixture
through the filler neck until the level reaches the
base of the filler neck.
12. Then replace the pressure cap. At any time during
this procedure if coolant begins to flow out of the
filler neck, reinstall the pressure cap. Be sure the
arrow on the pressure cap lines up like this.
13. Check the coolant in the recovery tank. The level in
the coolant recovery tank should be at the HOT
mark when the engine is hot or at the COLD mark
when the engine is cold.