2007 PONTIAC GRAND PRIX engine

Adding Coolant
If more coolant is needed, add the proper
DEX-COOL®coolant mixture at the coolant
recovery tank, but be careful not to spill it.
If the coolant recovery tank is completely empty,
add coolant to the radiator. SeeEngine
Overheating on page 364.
{CAUTION:
Turning the pressure cap when the
engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. With the coolant
recovery tank, you will almost never have
to add coolant at the radiator. Never turn
the pressure cap — even a little — when
the engine and radiator are hot.
{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 366.
363

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 346
for 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 180
andEngine Coolant Temperature Warning Light
on page 179.
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 366for
information on driving to a safe place in
an emergency.
364

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. See
Overheated Engine Protection Operating Mode
on page 366for 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.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.
365

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 350.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Recovery Tank
B. Electric Engine Cooling Fan(s)
C. Pressure Cap
3800 V6 Supercharged Engine shown,
3800 V6 Engine similar
366

A. Pressure Cap
B. Electric Engine Cooling Fans
C. Coolant Recovery Tank
{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 3800 V6
engines. 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.
5.3L V8 Engine
367

When the engine is cold, the coolant level should
be at or above the cold ll line on the coolant
recovery tank. To check the coolant level, look for
the cold ll 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.
{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. SeeOverheated Engine Protection
Operating Mode on page 366for 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 your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
368

How to Add Coolant to the Coolant
Recovery Tank
{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 would
not get the overheat warning. Your 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 ll line, add a
50/50 mixture of clean, drinkable water and
DEX-COOL
®engine coolant at the coolant
recovery tank. SeeEngine Coolant on page 360
for more information.
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.
369

When the coolant level in the coolant recovery
tank is at the cold ll 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.
How to Add Coolant to the Radiator
(3800 V6 Engines)
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.
3800 V6 Supercharged Engine shown,
3800 V6 Engine similar
370