2008 PONTIAC GRAND PRIX Owners Manual

{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. Do not spill coolant on a hot engine.
Occasionally check the coolant level in the radiator. For
information on how to add coolant to the radiator,
seeCooling System on page 5-30.
Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
SeeEngine Compartment Overview on page 5-12for
more information on location.
Engine Overheating
There is a coolant temperature gage and a warning light
on the instrument panel that indicate an overheated
engine condition. SeeEngine Coolant Temperature
Gage on page 3-49andEngine Coolant Temperature
Warning Light on page 3-48.
5-27

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from
the vehicle until it cools down. Wait until there
is no sign of steam or coolant before you open
the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the vehicle
until the engine is cool.
SeeOverheated Engine Protection Operating
Mode on page 5-29for information on driving to
a safe place in an emergency.Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty. SeeOverheated Engine
Protection Operating Mode on page 5-29for
information on driving to a safe place in an
emergency.
If No Steam is Coming From Your
Engine
An overheat warning can indicate a serious problem.
If you get an engine overheat warning but see or
hear no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
5-28

If an overheat warning occurs without any sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the heater at the highest setting and the fan at
the highest speed and open the windows as
necessary.
If the overheat warning no longer exists, the vehicle can
be driven. Just to be safe, drive slower for about
10 minutes. If the warning does not come back on, the
vehicle can be driven normally.
If the warning continues, and you have not stopped, pull
over, stop, and park the vehicle right away.
If there is still no sign of steam, idle the engine for three
minutes while parked. If the warning is still there, turn off
the engine and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine Protection
Operating Mode” later in this section.
You may decide not to lift the hood but to get service
help right away.Overheated Engine Protection
Operating Mode
The overheated engine protection operating mode
allows the vehicle to be driven to a safe place in an
emergency situation. If an overheated engine condition
exists, this protection mode alternates ring groups
of cylinders to help prevent engine damage. In this
mode, there will be a signicant loss in power and engine
performance. The engine coolant temperature gage
indicator will move to the shaded area, and the engine
coolant temperature warning light will come on, showing
that an overheated engine condition exists. Driving
extended miles (km) and/or towing a trailer in the
overheated engine protection mode should be avoided.
Notice: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. SeeEngine Oil on page 5-15.
5-29

Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Recovery Tank
B. Pressure Cap
C. Electric Engine Cooling Fan(s)A. Pressure Cap
B. Electric Engine Cooling Fans
C. Coolant Recovery Tank 3.8L V6 Engine
5.3L V8 Engine
5-30

{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,
do not do anything else until it cools down. The vehicle
should be parked on a level surface.The coolant recovery tank is located in the rear of the
engine compartment on the passenger’s side of the
vehicle on the 3.8L V6 engine. The coolant recovery
tank on the 5.3L V8 engine is located in the rear of the
engine compartment on the driver’s side of the vehicle,
behind the engine air cleaner/lter.
When the engine is cold, the coolant level should be at
or above the COLD FILL line on the coolant recovery
tank. To check the coolant level, look for the COLD FILL
line on the side of the coolant recovery tank that faces
the engine. If the level is not correct, there may be a leak
at the pressure cap or in the radiator hoses, heater
hoses, radiator, water pump, or somewhere else in the
cooling system.
5-31

{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them. If you
do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fan(s) are running.
If the engine is overheating, the fan(s) should be
running. If the fan(s) are not running, the vehicle
needs service.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-29for information on driving to a safe place
in an emergency.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)or 24 months, whichever occurs rst. Any repairs
would not be covered by the warranty. Always use
DEX-COOL
®(silicate-free) coolant in the vehicle.
How to Add Coolant to the Coolant
Recovery Tank
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
If you have not found a problem yet, but the coolant
level is not at the COLD FILL line, add a 50/50 mixture
of clean, drinkable water and DEX-COOL
®engine
coolant at the coolant recovery tank. SeeEngine
Coolant on page 5-24for more information.
5-32

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. Do not spill coolant on a hot engine.
When the coolant level in the coolant recovery tank is at
the COLD FILL line, start the vehicle.
If the overheat warning continues, there is one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the 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 pressure cap, is
hot. Wait for the cooling system and pressure
cap to cool if you ever have to turn the
pressure cap.
5-33

How to Add Coolant to the Radiator
(3.8L V6 Engine)
Notice:Your engine has a specic radiator ll
procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.
1. You can remove the pressure cap when the cooling
system, including the pressure cap and upper
radiator hose, is no longer hot. Turn the cap slowly
counterclockwise.
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 and remove it.{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. Do not spill coolant on a hot engine.
3. Remove the engine cover to access the
bleed valve.
3.1. Clean the area around the engine oil ll tube
and cap before removing. Twist the oil ll
tube, with cap attached, counterclockwise
and remove it.
3.8L V6 Engine
5-34