2004 CHEVROLET SILVERADO octane

If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling Your Tank on page 5-9. The
diagnostic system can determine if the fuel cap hasbeen left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to
x any mechanical or electrical problems that may
have developed.
3-49

Service............................................................5-3
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.......................................................5-7
Fuel E-85 (85% Ethanol).................................5-8
Fuels in Foreign Countries...............................5-9
Filling Your Tank............................................5-9
Filling a Portable Fuel Container.....................5-11
Checking Things Under the Hood....................5-12
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-20
Engine Air Cleaner/Filter................................5-25
Automatic Transmission Fluid
(Except Allison Transmission
®) ....................5-27
Automatic Transmission Fluid
(Allison Transmission
®) ...............................5-30
Manual Transmission Fluid.............................5-33
Hydraulic Clutch...........................................5-34Engine Coolant.............................................5-35
Coolant Surge Tank Pressure Cap..................5-38
Engine Overheating.......................................5-38
Cooling System............................................5-41
Engine Fan Noise.........................................5-46
Power Steering Fluid.....................................5-46
Windshield Washer Fluid................................5-47
Brakes........................................................5-49
Battery........................................................5-52
Jump Starting...............................................5-53
All-Wheel Drive..............................................5-58
Rear Axle.......................................................5-59
Four-Wheel Drive............................................5-60
Noise Control System.....................................5-61
Tampering with Noise Control System
Prohibited.................................................5-61
Bulb Replacement..........................................5-63
Halogen Bulbs..............................................5-63
Headlamps..................................................5-63
Front Turn Signal, Sidemarker and
Daytime Running Lamps.............................5-65
Roof Marker Lamps......................................5-66
Center High-Mounted Stoplamp (CHMSL)
and Cargo Lamp.......................................5-68
Section 5 Service and Appearance Care
5-1

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow 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
If your vehicle has a diesel engine, see “Diesel
Fuel Requirements and Fuel System” in the Diesel
Engine Supplement.
For vehicles with gasoline engines, please read this.
Gasoline Octane
For all except the Silverado SS model, 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.
If you have the Silverado SS model, use premium
unleaded gasoline with a posted octane of 91 or higher
for best performance. You may also use middle
grade or regular unleaded gasoline rated at 87 octane
or higher, but your vehicle’s acceleration may be slightly
reduced. If the octane is less than 87, you may get a
heavy knocking noise when you drive. If this occurs, use
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
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 specications 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.
5-7

Using Your Maintenance Schedule
We at General Motors want to help you keep your
vehicle in good working condition. But we do not know
exactly how you will drive it. You may drive very
short distances only a few times a week. Or you may
drive long distances all the time in very hot, dusty
weather. You may use your vehicle in making deliveries.
Or you may drive it to work, to do errands or in many
other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your GM Goodwrench dealer.
This schedule is for vehicles that:
carry passengers and cargo within recommended
limits. You will nd these limits on the tire and
loading information label. SeeLoading Your Vehicle
on page 4-56.
are driven on reasonable road surfaces within legal
driving limits.
are driven off-road in the recommended manner.
SeeOff-Road Driving on page 4-21.
use the recommended fuel. SeeGasoline Octane
on page 5-5.The services inScheduled Maintenance on page 6-4
should be performed when indicated. SeeAdditional
Required Services on page 6-6andMaintenance
Footnotes on page 6-8for further information.
{CAUTION:
Performing maintenance work on a vehicle can
be dangerous. In trying to do some jobs, you
can be seriously injured. Do your own
maintenance work only if you have the
required know-how and the proper tools and
equipment for the job. If you have any doubt,
see your GM Goodwrench dealer to have a
qualied technician do the work.
Some maintenance services can be complex. So,
unless you are technically qualied and have the
necessary equipment, you should have your GM
Goodwrench dealer do these jobs.
When you go to your GM Goodwrench dealer for your
service needs, you will know that GM-trained and
supported service technicians will perform the work
using genuine GM parts.
If you want to get service information, seeService
Publications Ordering Information on page 7-11.
6-3

Fluid
Automatic Transmission........................5-27, 5-30
Manual Transmission....................................5-33
Power Steering...........................................5-46
Windshield Washer......................................5-47
FM Stereo....................................................3-128
Fog Lamps....................................................3-16
Folding the Rear Seat....................................... 1-9
Following Distance..........................................4-91
Four-Wheel Drive....................................2-36, 5-60
Four-Wheel-Drive Light....................................3-51
Front Axle Locking Feature...............................2-36
Front Reading Lamps......................................3-18
Front Storage Area.........................................2-68
Fuel............................................................... 5-5
Additives...................................................... 5-7
California Fuel.............................................. 5-6
E-85 (85% Ethanol)....................................... 5-8
Filling a Portable Fuel Container....................5-11
Filling Your Tank........................................... 5-9
Fuels in Foreign Countries.............................. 5-9
Gage.........................................................3-52
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Low Warning Light.......................................3-53Fuel Information Button....................................3-56
FUEL LEVEL LOW.........................................3-66
Fuses
Fuses and Circuit Breakers.........................5-123
Windshield Wiper.......................................5-123
G
Gage
Engine Coolant Temperature.........................3-46
Fuel..........................................................3-52
Oil Pressure...............................................3-50
Speedometer..............................................3-35
Tachometer.................................................3-35
Transmission Temperature.............................3-46
Voltmeter Gage...........................................3-42
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-6
Getting Familiar with Off-Road Driving................4-25
Glove Box.....................................................2-67
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
7