2005 BUICK CENTURY octane

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline 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.Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-39

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....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your 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...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-24
Engine Overheating.......................................5-25
Overheated Engine Protection
Operating Mode........................................5-26
Cooling System............................................5-27Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
Headlamp Aiming...........................................5-45
Bulb Replacement..........................................5-47
Halogen Bulbs..............................................5-47
Headlamps..................................................5-47
Front Turn Signal and Parking Lamps................5-48
Center High-Mounted Stoplamp (CHMSL).........5-49
Taillamps, Turn Signal, and Stoplamps............5-50
Back-Up Lamps............................................5-51
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-53
Tire Sidewall Labelling...................................5-54
Tire Terminology and Denitions.....................5-57
Ination - Tire Pressure.................................5-60
Tire Pressure Monitor System.........................5-61
Tire Inspection and Rotation...........................5-63
When It Is Time for New Tires.......................5-64
Buying New Tires.........................................5-64
Uniform Tire Quality Grading..........................5-65
Wheel Alignment and Tire Balance..................5-67
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
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
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.
Gasoline Specications
It is recommended that gasoline meet specications
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/fuel_charter.htm. Gasoline
meeting these specications could provide improved
driveability and emission control system performance
compared to other gasoline.
5-5

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 nd. 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.
5-7

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 4-31.
are driven on reasonable road surfaces within legal
driving limits.
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.
Owner Checks and Services on page 6-9tells you what
should be checked, when to check it and what you can
easily do to help keep your vehicle in good condition.
The proper replacement parts, uids and lubricants to
use are listed inRecommended Fluids and Lubricants
on page 6-13andNormal Maintenance Replacement
Parts on page 6-14. When your vehicle is serviced,
make sure these are used. All parts should be replaced
and all necessary repairs done before you or anyone
else drives the vehicle. We recommend the use of
genuine GM parts.
6-3

Event Data Recorders (EDR)............................. 7-9
Extender, Safety Belt.......................................1-26
Exterior Lamps...............................................3-13
F
Filter
Engine Air Cleaner......................................5-18
Finish Damage...............................................5-88
Fixed Mast Antenna........................................3-66
Flash-to-Pass................................................... 3-8
Flat Tire........................................................5-69
Flat Tire, Changing.........................................5-70
Flat Tire, Storing.............................................5-79
Fluid
Automatic Transaxle.....................................5-19
Power Steering...........................................5-34
Windshield Washer......................................5-35
Folding Rear Seat............................................ 1-6
Front Storage Area.........................................2-33
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
Filling a Portable Fuel Container....................5-10
Filling Your Tank........................................... 5-8
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-42
Gasoline Octane........................................... 5-5Fuel (cont.)
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-43
Fuses
Fuses and Circuit Breakers...........................5-91
Instrument Panel Fuse Block.........................5-91
Underhood Fuse Block.................................5-94
Windshield Wiper.........................................5-91
G
Gage
Engine Coolant Temperature.........................3-35
Fuel..........................................................3-42
Speedometer..............................................3-30
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-33
GM Mobility Program for Persons
with Disabilities............................................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-5
Headlamp
Aiming.......................................................5-45
5