2003 PONTIAC GRAND PRIX engine

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need a
different turn signal flasher and/or extra wiring. Check
with your dealer. The arrows on your instrument
panel will flash whenever you signal a turn or lane
change. Properly hooked up, the trailer lamps will also
flash, telling other drivers you’re about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Your vehicle has bulb warning lights. When you plug a
trailer lighting system into your vehicle’s lighting
system, its bulb warning lights may not let you know
if
one of your lamps goes out. So, when you have a trailer
lighting system plugged in, be sure to check your
vehicle and trailer lamps from time to time to be sure
they’re all working. Once you disconnect the trailer
lamps, the bulb warning lights again can tell you
if one
of your vehicle lamps is out.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
On a long uphill grade, shift down and reduce your
speed to around
45 mph (70 km/h) to reduce the
possibility of engine and transaxle overheating.
If you have overdrive, you may have to drive in
THIRD (3) instead of AUTOMATIC OVERDRIVE (D).
Parking on Hills
1 -J really should not ,,rk yo^, wG,kle, 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.
4-42

But if you ever have to park your rig on a hill, here’s
how to do it:
1.
2.
3.
4.
5.
Apply your regular brakes, but don’t shift into
PARK
(P) yet.
Have someone place chocks under the trailer
wheels.
When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
Reapply the regular brakes. Then apply your
parking brake, and then shift to PARK
(P).
Release the regular brakes.
When You Are Ready to Leave After
Parking on a
Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
0 shift into a gear, and
0 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
Your vehicle will need service more often when you’re
pulling a trailer. See Part
A: Scheduled Maintenance
Services on page
6-4 for more information. Things that
are especially important in trailer operation are
automatic transaxle fluid (don’t overfill), engine oil, drive
belts, cooling system and brake system. Each of
these is covered in this manual, and the Index will help
you find them quickly.
If you’re trailering, it’s a good
idea to review this information before you start your trip.
Check periodically
to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. See Engine Overheating
on page
5-33.
4-43

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your
Owr? Service Work ......................... 5-4
Adding Equipment to the Outside of
Your Vehicle
.............................................. 5-4
Fuel ................................................................ 5-5
Gasoline Octane
............................................ 5-5
Gasoline Specifications
.................................... 5-5
California Fuel
............................................... 5-6
Additives
....................................................... 5-6
Fuels in Foreign Countries
............................... 5-7
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container
....................... 5-9
Checking Things Under the Hood .................... 5-10
Hood Release
.............................................. 5-10
Engine Compartment Overview
....................... 5-12
Engine Oil
................................................... 5-18
Supercharger Oil
.......................................... 5-24
Engine Air CleanedFilter
................................ 5-25
Automatic Transaxle Fluid
.............................. 5-27
Engine Coolant
............................................. 5-30
Radiator Pressure Cap
.................................. 5-33
Cooling System
........................................... -5-36
Power Steering Fluid
..................................... 5-46
Windshield Washer Fluid
................................ 5-48
Engine Overheating
....................................... 5-33 Brakes
........................................................ 5.49
Battery
........................................................ 5.52
Jump Starting
............................................... 5-53
Bulb Replacement .......................................... 5-60
Halogen Bulbs
.............................................. 5-60
Headlamps
.................................................. 5-60
Front Turn Signal and Sidemarker Lamps
........ 5-62
Center High-Mounted Stoplamp (CHMSL)
......... 5-63
Taillamps, Sidemarker and Back-up Lamps
...... 5-64
Replacement Bulbs
....................................... 5-66
Windshield Wiper Blade Replacement .............. 5-67
Tires ............................................................. -5-68
Inflation
-- Tire Pressure ................................ 5-68
Tire Inspection and Rotation
........................... 5-69
When It
Is Time for New Tires ....................... 5-70
Buying New Tires
......................................... 5-71
Uniform Tire Quality Grading
.......................... 5-72
Wheel Replacement
...................................... 5-73
Headlamp Aiming ........................................... 5-59
Wheel Alignment and Tire Balance
.................. 5-73
Tire Chains
.................................................. 5-75
If a Tire Goes Flat ........................................ 5-76
Changing a Flat Tire
..................................... 5-76
Compact Spare Tire
...................................... 5-87
5- 1

Gasoline Specifications
The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You will find the ViN at the top left of the
instrument panel. See Vehicle Identification
Number (VIN) on page
5-96.
Gasoline Octane
If your vehicle has the 31 00 V6 engine (VIN Code J) or
3800 V6 engine (VIN Code
K), use regular unleaded
gasoline with a posted octane of 87 or higher.
If the
octane is less than 87, you may get a heavy knocking
noise when you drive. If
it is bad enough, it can damage
your engine. A little pinging noise when you accelerate or
drive uphill is considered normal. This does not indicate
a
problem exists or that a higher-octane fuel is necessary.
If your vehicle has the 3800 Supercharged V6 engine
(VIN Code I), use only premium unleaded gasoline with
a
posted octane of 91 or higher. In an emergency, you may
be able
to use a lower octane - as low a 87 - if heavy
knocking does not occur. Refill your tank with premium
fuel
as soon as possible. If you are using 91 octane or
higher-octane fuel and you hear knocking, your engine
needs service. It
is recommended that gasoline meet specifications
which were developed by the American Automobile
Manufacturers Association and endorsed by the
Canadian Vehicle Manufacturers Association for better
vehicle performance and engine protection. Gasoline
meeting these specifications could provide improved
driveability and emission control system performance
compared
to other gasoline.
Canada Only
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
5-5

California Fuel Additives
If
your vehicle is certified to meet California Emission
Standards (see the underhood emission control label),
it is designed to operate on fuels that meet California
specifications. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see Malfunction Indicator
Lamp on page 3-32)
and your vehicle may fail a smog-check test. If this
occurs, return to your authorized
GM dealer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs may not be covered
by your warranty. To
provide cleaner air, all gasolines in the United States
are now required
to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. Gasolines containing oxygenates, such as
ethers and ethanol, and reformulated gasolines may be
available in your area to contribute to clean air.
General Motors recommends that you use these
gasolines, particularly
if they comply with the
specifications described earlier.
Notice: Your vehicle was not designed for fuel that
contains methanol. Don’t use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage wouldn’t be covered under your
warranty.
5-6

Checking Things Under
the
Hood
Ar. Jectric fan unl,.' the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing and tools away
from any underhood electric fan.
Hood Release
To open the hood do the following:
Things that burn can get on ..__ -.. 3"'- parts
and start
a fire. These include liquids like fuel,
oil, coolant, brake fluid, windshield washer and
other fluids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that
will burn onto a hot engine.
1. Pull the handle located
inside the vehicle near
the parking brake.
5-1 0

Engine Compartment Overview
When you open the hood of a vehicle with a 3100 V6 (Code J) engine, you’ll see:
5-1 2

A. Windshield Washer Fluid Reservoir
B. Battery
C. Underhood Fuse Block
B. Remote Positive (+) Battery Terminal
E. Radiator Pressure Cap
F. Engine Coolant Recovery Tank
G. Power Steering Fluid Reservoir
(low in engine compartment, below generator)
H. Electric Engine Cooling Fan
I. Engine Oil Fill Cap
J. Engine Oil Dipstick
K. Automatic Transaxle Fluid Dipstick
L. Brake Fluid Reservoir
M. Engine Air CleanedFilter
5-1 3