2004 GMC SONOMA fuel

Just before you leave the lane, glance quickly over your
shoulder to make sure there is not another vehicle in
your “blind” spot.
Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to
move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your exit, do
not, under any circumstances, stop and back up. Drive
on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are
going slower than you actually are.Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested. If you
must start when you are not fresh — such as after
a day’s work — do not plan to make too many miles that
first part of the journey. Wear comfortable clothing
and shoes you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it needs
service, have it done before starting out. Of course, you
will find experienced and able service experts in GM
dealerships all across North America. They will be ready
and willing to help if you need it.
Here are some things you can check before a trip:
•Windshield Washer Fluid:Is the reservoir full? Are
all windows clean inside and outside?
•Wiper Blades:Are they in good shape?
•Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
•Lamps:Are they all working? Are the lenses clean?
4-34

{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can not see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
4-41

Refer to your vehicle’s tire and loading information label
for specific information about your vehicle’s capacity
and seating positions. The combined weight of the
driver, passengers and cargo should never exceed your
vehicle’s capacity weight.Certication/Tire Label
The Certification/Tire label is found on the driver’s door
edge, above the door latch. The label shows the
size of your original tires and the inflation pressures
needed to obtain the gross weight capacity of your
vehicle. This is called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight of the
vehicle, all occupants, fuel, cargo and trailer tongue
weight, if pulling a trailer.
4-49

Towing a Trailer
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.
Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs that would
not be covered by your warranty. Always follow
the instructions in this section and check with your
dealer for more information about towing a trailer
with your vehicle.Your vehicle may be able to tow a trailer. To identify
what the vehicle trailering capacity is for your vehicle,
you should read the information in “Weight of the Trailer”
that appears later in this section.
If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, accelleration, braking, durability
and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully before
you pull a trailer.
4-55

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of
Your Vehicle..............................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specifications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
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...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
Rear Axle.......................................................5-46
Four-Wheel Drive............................................5-46
Front Axle......................................................5-47
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-49
One-Piece Front Turn Signal Lamps................5-51
Two-Piece Front Turn Signal Lamps................5-51
Center High-Mounted Stoplamp (CHMSL).........5-52
Taillamps.....................................................5-53
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Inflation - Tire Pressure.................................5-67
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Uniform Tire Quality Grading..........................5-71
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-72
Section 5 Service and Appearance Care
5-1

CAUTION: (Continued)

Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind
noise and affect windshield washer performance. Check
with your dealer before adding equipment to the
outside of your vehicle.
Fuel
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. SeeVehicle Identication
Number (VIN) on page 5-94.
Gasoline Octane
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 this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you might 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 you are using 87 octane or higher-octane
fuel and hear heavy knocking, your engine needs
service.
5-4

Gasoline Specications
It is recommended that gasoline meet specifications
which were developed by automobile manufacturers
around the world and contained in the World-Wide
Fuel Charter which is available from the Alliance
of Automobile Manufacturers at www.autoalliance.org.
Gasoline meeting these specifications could provide
improved driveability and emission control system
performance compared to other gasoline.
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
California Fuel
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 (seeMalfunction Indicator Lamp on page 3-29)
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.
Canada Only
5-5

Additives
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. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems due
to dirty injectors or valves, try a different brand of
gasoline.
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. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT. General
Motors does not recommend the use of such gasolines.
Fuels containing MMT can reduce the life of spark
plugs and the performance of the emission control
system may be affected. The malfunction indicator lamp
may turn on. If this occurs, return to your authorized
GM dealer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-6