2008 PONTIAC GRAND PRIX engine overheat

The vehicle has bulb warning lights. When a trailer
lighting system is plugged into the vehicle’s lighting
system, its bulb warning lights may not indicate if one of
the lamps goes out. So, when a trailer lighting system
is plugged in, be sure to check the vehicle and
trailer lamps from time to time to be sure they are all
working. Once the trailer lamps have been disconnected,
the bulb warning lights can once again indicate if one
of the vehicle lamps is out.
Driving On Grades
Reduce speed and shift to a lower gear before starting
down a long or steep downgrade. If the vehicle is
not shifted down, the brakes may have to be used so
much that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of engine and transmission overheating.
If the vehicle has overdrive, it may be driven in
THIRD (3) instead of DRIVE (D).
Parking on Hills
{CAUTION:
You really should not park your vehicle, with
a trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if the rig ever has to be parked on a hill, here is
how to do it:
1. Apply the regular brakes, but do not shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply the
parking brake, and then shift to PARK (P).
5. Release the regular brakes.
4-35

When You Are Ready to Leave After
Parking on a Hill
1. Apply the regular brakes and hold the pedal
down while you:
Start the engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store
the chocks.
Maintenance When Trailer Towing
The vehicle will need service more often when it
pulls a trailer. SeeScheduled Maintenance on page 6-4
for more information. Things that are especially
important in trailer operation are automatic transmission
uid, which should not be overlled, engine oil, drive
belts, cooling, and brake systems. Each of these
is covered in this manual, and the Index will help locate
them quickly. If trailering, it is a good idea to review
this information before starting on a trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating
on page 5-27.
4-36

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Pressure Cap...............................................5-27
Engine Overheating.......................................5-27Overheated Engine Protection
Operating Mode........................................5-29
Cooling System............................................5-30
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-45
Jump Starting...............................................5-46
Headlamp Aiming...........................................5-51
Bulb Replacement..........................................5-54
Halogen Bulbs..............................................5-54
Headlamps and Sidemarker Lamps.................5-54
Front Turn Signal, Parking and Fog Lamps......5-57
Taillamps, Turn Signal, and Stoplamps............5-58
Back-Up Lamps............................................5-59
License Plate Lamp......................................5-60
Replacement Bulbs.......................................5-60
Windshield Replacement.................................5-61
Windshield Wiper Blade Replacement..............5-61
Tires..............................................................5-62
Tire Sidewall Labeling...................................5-63
Tire Terminology and Denitions.....................5-66
Ination - Tire Pressure.................................5-69
Tire Pressure Monitor System.........................5-71
Section 5 Service and Appearance Care
5-1

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check the automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-12.
How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re. Too
little uid could cause the transmission to overheat.
Be sure to get an accurate reading if you check your
transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it is colder than 50°F (10°C), you may have to
drive longer.
5-22

If the uid level is low, add only enough of the proper
uid to bring the level into the crosshatched area on the
dipstick.
1. Pull out the dipstick.
2. Using a long-neck funnel, add enough uid at the
dipstick hole to bring it to the proper level.
It does not take much uid, generally less than one
pint (0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always use
the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
3. After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
4. When the correct uid level is obtained, push the
dipstick back in all the way.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if only
DEX-COOL
®extended life coolant is added.The following explains the cooling system and how to
add coolant when it is low. If there is a problem with
engine overheating or if coolant needs to be added to the
radiator, seeEngine Overheating on page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®engine coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 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.
5-24

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®engine coolant which will not
damage aluminum parts. If this coolant mixture is used,
nothing else needs to be added.
{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.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
If coolant needs to be added more than four times a
year, have your dealer/retailer check the cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. Use only the proper mixture
of the engine coolant listed in this manual for
the cooling system. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
5-25

Checking Coolant
The coolant recovery tank
cap has this symbol on it.
SeeEngine Compartment Overview on page 5-12for
more information on the location of the coolant
recovery tank.
The vehicle must be on a level surface when checking
the coolant level.
When the engine is cold, the coolant level should be at
the cold ll line or a little higher. The cold ll line is
marked with the same symbol as the coolant recovery
tank cap.
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 5-27.
{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.
5-26

{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