2004 BUICK CENTURY check oil

A. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-36.
B. Battery. SeeBattery on page 5-41.
C. Underhood Fuse Block. SeeFuses and Circuit
Breakers on page 5-97.
D. Remote Positive (+) Battery Terminal. SeeJump
Starting on page 5-42.
E. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-25.
F. Engine Coolant Recovery Tank. SeeEngine Coolant
on page 5-22.
G. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-35.
H. Electric Engine Cooling Fan. SeeJump Starting on
page 5-42.
I. Engine Oil Fill Cap. SeeEngine Oil on page 5-13.
J. Engine Oil Dipstick. SeeEngine Oil on page 5-13.
K. Automatic Transaxle Fluid Dipstick. SeeAutomatic
Transaxle Fluid on page 5-19.
L. Brake Fluid Reservoir. SeeBrakes on page 5-38.
M. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.Engine Oil
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
5-13

Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
®oil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an
SAE 5W-30 synthetic oil or an SAE 0W-30 oil. Both will
provide easier cold starting and better protection for
your engine at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
When to Change Engine Oil
(GM Oil Life 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.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE 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.
5-16

Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12for
location of engine air cleaner/lter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/lter at every oil change
and replace at the rst oil change after 25,000 miles
(40 000 km).
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/lter remove it from the
vehicle and lightly shake the lter to release loose dust
and dirt. If the lter remains caked with dirt, a new
lter is required.
To check or replace the engine air cleaner/lter, do the
following:
1. Loosen the screw and clamp on the air duct.2. Lift the two clips
located on the top of
the lter assembly
to unlock the cover.
3. Disconnect the duct and reposition it while removing
the cover.
4. Pull out the lter.
5. Inspect or replace the lter if needed.
6. Reinstall the lter.
7. Push the two clips located on top of the lter
assembly to lock the cover.
5-18

{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it helps to
stop ame if the engine backres. If it is not
there and the engine backres, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
Automatic Transaxle Fluid
When to Check and Change
A good time to check the automatic transaxle uid level
is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If the vehicle is not used under any of these conditions,
change the uid and lter at 100,000 miles
(166 000 km).
SeeScheduled Maintenance on page 6-4.
5-19

Cleaning Exterior Lamps/Lenses
Use only lukewarm or cold water, a soft cloth and a car
washing soap to clean exterior lamps and lenses.
Follow instructions under “Washing Your Vehicle.”
Finish Care
Occasional waxing or mild polishing of your vehicle by
hand may be necessary to remove residue from the
paint nish. You can get GM-approved cleaning products
from your dealer. SeeVehicle Care/Appearance
Materials on page 5-95.
Your vehicle has a “basecoat/clearcoat” paint nish. The
clearcoat gives more depth and gloss to the colored
basecoat. Always use waxes and polishes that are
non-abrasive and made for a basecoat/clearcoat paint
nish.
Notice:Machine compounding or aggressive
polishing on a basecoat/clearcoat paint nish may
damage it. Use only non-abrasive waxes and
polishes that are made for a basecoat/clearcoat
paint nish on your vehicle.
Foreign materials such as calcium chloride and other
salts, ice melting agents, road oil and tar, tree sap, bird
droppings, chemicals from industrial chimneys, etc.,
can damage your vehicle’s nish if they remainon painted surfaces. Wash the vehicle as soon as
possible. If necessary, use non-abrasive cleaners that
are marked safe for painted surfaces to remove
foreign matter.
Exterior painted surfaces are subject to aging, weather
and chemical fallout that can take their toll over a
period of years. You can help to keep the paint nish
looking new by keeping your vehicle garaged or covered
whenever possible.
Cleaning Windshield and Wiper Blades
If the windshield is not clear after using the windshield
washer, or if the wiper blade chatters when running,
wax, sap or other material may be on the blade
or windshield.
Clean the outside of the windshield with a full-strength
glass cleaning liquid. The windshield is clean if beads do
not form when you rinse it with water.
Grime from the windshield will stick to the wiper blades
and affect their performance. Clean the blade by
wiping vigorously with a cloth soaked in full-strength
windshield washer solvent. Then rinse the blade
with water.
Check the wiper blades and clean them as necessary;
replace blades that look worn.
5-92

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.
Maintenance Requirements
Notice:Maintenance intervals, checks, inspections,
replacement parts 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.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance is
important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper uid
levels or the wrong tire ination 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.
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.
6-2

Scheduled Maintenance
When the CHANGE OIL SOON light comes on, it
means that service is required for your vehicle. Have
your vehicle serviced as soon as possible within the
next 600 miles (1 000 km). It is possible that, if you
are driving under the best conditions, the engine oil
life system may not indicate that vehicle service
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 GM
Goodwrench dealer has GM-trained service technicians
who will perform this work using genuine GM parts
and reset the system.
If the engine oil life system is ever reset accidentally,
you must service your vehicle within 3,000 miles
(5 000 km) since your last service. Remember to reset
the oil life system whenever the oil is changed. See
Engine Oil on page 5-13for information on the Engine
Oil Life System and resetting the system.When the CHANGE OIL SOON light appears,
certain services, checks and inspections are required.
Required services are described in the following for
“MaintenanceI” and “MaintenanceII.” Generally,
it is recommended that your rst service be
MaintenanceI, your second service be MaintenanceII
and that you alternate MaintenanceIand MaintenanceII
thereafter. However, in some cases, MaintenanceII
may be required more often.
MaintenanceI— Use MaintenanceIif the light comes
on within ten months since vehicle was purchased or
MaintenanceIIwas performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the light comes on ten months
or more since the last service or if the light has not
come on at all for one year.
6-4

Service MaintenanceIMaintenanceII
Change engine oil and lter. Reset oil life system. SeeEngine Oil on
page 5-13.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-18.An Emission Control Service. See footnote †.••
Rotate tires and check ination pressures and wear. SeeTires on page 5-57.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
Perform any needed additional services. See “Additional Required Services” in
this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transaxle uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
Inspect throttle system.See footnote (j).•
6-5