2003 BUICK CENTURY engine

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. Improper vehicle maintenance can
even affect the quality of the air we breathe. Improper
¯uid levels or the wrong tire in¯ation can increase
the level of emissions from your vehicle. To help protect
our environment, and to keep your vehicle in good
condition, be sure to maintain your vehicle properly.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended ¯uids and lubricants as prescribed in this
manual are necessary to keep your vehicle in good
working condition. Any damage caused by failure
to follow scheduled maintenance may not be covered by
warranty.
6-2

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