service BUICK CENTURY 2003 Workshop Manual

How This Section is Organized
This maintenance schedule is divided into ®ve parts:
ªPart A: Scheduled Maintenance Servicesºexplains
what to have done and how often. Some of these
services can be complex, so unless you are technically
quali®ed and have the necessary equipment, you should
let your GM dealer's service department do these jobs.
Your GM dealer has GM-trained and supported service
people that will perform the work using genuine GM parts.
{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,
have a quali®ed technician do the work.
If you want to get the service information, see
Service
Publications Ordering Information on page 7-11.ªPart B: Owner Checks and Servicesºtells you what
should be checked and when. It also explains what
you can easily do to help keep your vehicle in good
condition.
ªPart C: Periodic MaintenanceInspectionsºexplains
important inspections that your dealer's service
department can perform for you.
ªPart D: Recommended Fluids and Lubricantsºlists
some recommended products necessary to help
keep your vehicle properly maintained. These products,
or their equivalents, should be used whether you do
the work yourself or have it done.
ªPart E: Maintenance Recordºis a place for you to
record and keep track of the maintenance performed on
your vehicle. Keep your maintenance receipts. They may
be needed to qualify your vehicle for warranty repairs.
6-3

Part A: Scheduled Maintenance
Services
This part contains engine oil scheduled maintenance
which explains the engine oil life system and how
it indicates when to change the engine oil and ®lter.
Also, listed are scheduled maintenance services which
are to be performed at the mileage intervals speci®ed.
Using Your Maintenance Schedule
We at General Motors want to keep your vehicle in good
working condition. But we don't know exactly how
you'll drive it. You may drive 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 the different ways people use their vehicles,
maintenance needs may vary. You may need more
frequent checks and replacements. So please read the
following and note how you drive. If you have
questions on how to keep your vehicle in good condition,
see your dealer.This part tells you the maintenance services you should
have done and when to schedule them.
When you go to your dealer for your service needs,
you'll know that GM-trained and supported service
people will perform the work using genuine GM parts.
The proper ¯uids and lubricants to use are listed in Part
D. Make sure whoever services your vehicle uses these.
All parts should be replaced and all necessary repairs
done before you or anyone else drives the vehicle.
This schedule is for vehicles that:·carry passengers and cargo within recommended
limits. You will ®nd these on your vehicle's
Tire-Loading Information label. See
Loading Your
Vehicle on page 4-33.
·are driven on reasonable road surfaces within legal
driving limits.
·use the recommended fuel. SeeGasoline Octane
on page 5-5
.
6-4

Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
See
Part B: Owner Checks and Services on page 6-10andPart C: Periodic MaintenanceInspections on
page 6-14.
Footnotes
²The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.Whenever the tires are rotated, the Tire In¯ation Monitor
System must be reset.
+A good time to check your brakes is during tire
rotation. See Brake System Inspection on page 6-15.
Engine Oil Scheduled Maintenance
Change engine oil and ®lter as indicated by the GM
Oil Life System (or every 12 months, whichever
occurs ®rst). Reset the system.
Your vehicle has a computer system that lets you know
when to change the engine oil and ®lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.
6-5

When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL SOON light will
come on. Change your oil as soon as possible within the
next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil
life system may not indicate that an oil change is
necessary for over a year. However, your engine oil and
®lter must be changed at least once a year and at
this time the system must be reset. Your dealer has
GM-trained service people who will perform this
work using genuine GM parts and reset the system.
It is also important to check your oil regularly and keep
it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed. See
Engine Oil on
page 5-13for information on resetting the system.
An Emission Control Service.
See the mileage intervals following for additional
services that may be performed with an engine oil
change. After the services are performed, record the
date, odometer reading and who performed the service
on the maintenance record pages in Part E of this
schedule.
7,500 Miles (12 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
15,000 Miles (25 000 km)
qInspect engine air cleaner ®lter. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect ®lter at every engine oil change. See
Engine Air Cleaner/Filter on page 5-18for more
information.An Emission Control Service. (See
footnote ².)
qReplace passenger compartment air ®lter. If you
drive regularly under dusty conditions, the ®lter
may require replacement more often.
qRotate tires. See
Tire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
22,500 Miles (37 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
6-6

30,000 Miles (50 000 km)
qReplace passenger compartment air ®lter. If you
drive regularly under dusty conditions, the ®lter
may require replacement more often.
qRotate tires. See
Tire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
qReplace engine air cleaner ®lter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An Emission Control Service.
37,500 Miles (62 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
45,000 Miles (75 000 km)
qInspect engine air cleaner ®lter. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect ®lter at every engine oil change. See
Engine
Air Cleaner/Filter on page 5-18for more information.An Emission Control Service. (See footnote ².)
qReplace passenger compartment air ®lter. If you drive
regularly under dusty conditions, the ®lter may require
replacement more often.
qRotate tires. See
Tire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
50,000 Miles (83 000 km)
qChange automatic transaxle ¯uid and ®lter if the
vehicle is mainly driven under one or more of
these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC) or
higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the ¯uid and ®lter at 100,000 miles
(166 000 km).
6-7

52,500 Miles (87 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
60,000 Miles (100 000 km)
qReplace passenger compartment air ®lter. If you
drive regularly under dusty conditions, the ®lter
may require replacement more often.
qRotate tires. See
Tire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
qReplace engine air cleaner ®lter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An Emission Control Service.
67,500 Miles (112 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
75,000 Miles (125 000 km)
qInspect engine air cleaner ®lter. If necessary, replace
the ®lter. If vehicle is driven in dusty/dirty conditions,
inspect ®lter at every engine oil change. See
Engine Air Cleaner/Filter on page 5-18for more
information.An Emission Control Service. (See
footnote ².)
qReplace passenger compartment air ®lter. If you
drive regularly under dusty conditions, the ®lter
may require replacement more often.
qRotate tires. See
Tire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
82,500 Miles (137 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
6-8

90,000 Miles (150 000 km)
qReplace passenger compartment air ®lter. If you
drive regularly under dusty conditions, the ®lter
may require replacement more often.
qReplace engine air cleaner ®lter. See
Engine Air
Cleaner/Filter on page 5-18for more information.An Emission Control Service.
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
97,500 Miles (162 500 km)
qRotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote .) (See footnote +.)
100,000 Miles (166 000 km)
qInspect spark plug wires.An Emission Control
Service.
qReplace spark plugs.An Emission Control Service.
qChange automatic transaxle ¯uid and ®lter if the
vehicle is mainly driven under one or more of
these conditions:
þ In heavy city traffic where the outside
temperature regularly reaches 90ÉF (32ÉC)
or higher.
þ In hilly or mountainous terrain.
þ When doing frequent trailer towing.
þ Uses such as found in taxi, police or delivery
service.
qIf you haven't used your vehicle under severe service
conditions listed previously and, therefore, haven't
changed your automatic transaxle ¯uid, change both
the ¯uid and ®lter.
150,000 Miles (240 000 km)
qDrain, ¯ush and re®ll cooling system (or every
60 months since last service, whichever occurs ®rst).
See
Engine Coolant on page 5-23for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.
An Emission Control Service.
qInspect engine accessory drive belt.An Emission
Control Service.
6-9

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals speci®ed to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any ¯uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in Part D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel ®ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOLž
coolant mixture if necessary. SeeEngine Coolant
on page 5-23for further details.
Windshield Washer Fluid Level Check
Check the windshield washer ¯uid level in the windshield
washer tank and add the proper ¯uid if necessary.
See
Windshield Washer Fluid on page 5-38for further
details.
At Least Once a Month
Tire In¯ation Check
Make sure tires are in¯ated to the correct pressures.
Don't forget to check your spare tire. SeeTires on
page 5-57for further details.
Cassette Tape Player Service
Clean cassette tape player. Cleaning should be done
every 50 hours of tape play. SeeAudio System(s)
on page 3-39for further details.
6-10

At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
ªWindshield Wiper and Wiper Bladesº under
Cleaning
the Outside of Your Vehicle on page 5-82.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,damp weather more frequent application may be
required. See
Part D: Recommended Fluids and
Lubricants on page 6-16.
Automatic Transaxle Check
Check the transaxle ¯uid level; add if needed. SeeAutomatic Transaxle Fluid on page 5-19. A ¯uid loss
may indicate a problem. Check the system and repair if
needed.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
speci®ed in Part D.
Body Lubrication Service
Lubricate all hinges and latches, including those for the
body doors, hood, secondary latch, pivots, spring
anchor, release pawl, rear compartment, glove box door
and console door. Part D tells you what to use. More
frequent lubrication may be required when exposed to a
corrosive environment.
6-11

Starter Switch Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. See
Parking Brake on page 2-26if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The starter
should work only in PARK (P) or NEUTRAL (N).
If the starter works in any other position, your
vehicle needs service.
Automatic Transaxle Shift Lock Control
System Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. See
Parking Brake
on page 2-26if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.
6-12