2007 PONTIAC GRAND PRIX engine overheat

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

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

10. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan(s).
11. By this time, the coolant level inside the
radiator ller neck may be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.12. Then replace the pressure cap. At any time
during this procedure if coolant begins to ow
out of the ller neck, reinstall the pressure
cap. Be sure the pressure cap is hand-tight
and fully seated.
13. Check the coolant in the recovery tank. The
level in the coolant recovery tank should be
at the cold ll line when the engine is cold.
How to Add Coolant to the Cooling
System (5.3L V8 Engine)
Notice:Your engine has a specic cooling
system drain and ll procedure. Failure
to follow this procedure could cause your
engine to overheat and be severely damaged.
If your engine’s cooling system needs to
be drained and re-lled, please see your dealer.
3800 V6 Supercharged Engine shown,
3800 V6 Engine similar
374

Driving
At Night................................................... 302
City.......................................................... 306
Defensive................................................. 284
Drunken................................................... 285
Freeway................................................... 307
Hill and Mountain Roads.......................... 309
In Rain and on Wet Roads...................... 303
Rocking Your Vehicle to Get it Out.......... 316
Winter...................................................... 311
Dual Automatic Climate Control System....... 162
E
Electric Power Management........................ 150
Electrical System
Add-On Equipment................................... 459
Fuses and Circuit Breakers...................... 460
Headlamp Wiring..................................... 459
Instrument Panel Fuse Block................... 460
Power Windows and Other Power
Options................................................. 459
Underhood Fuse Block............................. 462
Windshield Wiper Fuses........................... 459Engine
Air Cleaner/Filter...................................... 355
Battery..................................................... 381
Check and Service Engine Soon Light..... 180
Coolant.................................................... 360
Coolant Heater......................................... 108
Coolant Temperature Gage...................... 180
Coolant Temperature Warning Light.......... 179
Drive Belt Routing.................................... 485
Engine Compartment Overview ................ 346
Exhaust................................................... 119
Oil ........................................................... 350
Oil Life System........................................ 353
Overheated Protection Operating Mode.... 366
Overheating............................................. 364
Starting.................................................... 107
Supercharger Oil...................................... 355
Enhanced Traction System (ETS) ................ 293
Warning Light........................................... 179
Entry Lighting.............................................. 148
Event Data Recorders (EDR)...................... 504
Extender, Safety Belt..................................... 38
Exterior Lamps............................................ 144
Exterior Lighting Battery Saver.................... 146
517

M
Maintenance Schedule
Additional Required Services.................... 476
At Each Fuel Fill...................................... 479
At Least Once a Month............................ 480
At Least Once a Year.............................. 480
Introduction.............................................. 470
Maintenance Footnotes............................ 477
Maintenance Record................................ 487
Maintenance Requirements...................... 470
Normal Maintenance Replacement Parts.... 484
Owner Checks and Services.................... 479
Recommended Fluids and Lubricants....... 483
Scheduled Maintenance........................... 473
Using....................................................... 471
Your Vehicle and the Environment............ 471
Malfunction Indicator Light........................... 180
Manual Passenger Seat.................................. 8
Message
DIC Warnings and Messages................... 200
Mirrors
Manual Rearview Mirror with OnStar
®...... 121
Outside Convex Mirror............................. 122
Outside Power Mirrors............................. 121
MP3 ............................................................ 269
MyGMLink.com............................................ 495
N
New Vehicle Break-In.................................. 105
Normal Maintenance Replacement Parts..... 484
O
Odometer.................................................... 170
Off-Road Recovery...................................... 299
Oil
Engine..................................................... 350
Pressure Light.......................................... 184
Supercharger, Engine............................... 355
Oil, Engine Oil Life System......................... 353
Older Children, Restraints............................. 39
Online Owner Center................................... 495
OnStar
®System, see OnStar®Manual........ 122
Other Warning Devices................................ 134
Outlet Adjustment........................................ 166
Outlet(s), Accessory Power.......................... 156
Outside
Convex Mirror.......................................... 122
Power Mirrors.......................................... 121
Overhead Console Reading Lamps............. 149
Overheated Engine Protection
Operating Mode....................................... 366
Owner Checks and Services....................... 479
Owners, Canadian.......................................... 3
521