2000 BUICK CENTURY Owner's Manual

6-15 Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.
When to Change Engine Oil
Your vehicle has a computer that lets you know when to
change your engine oil. This is not based on mileage,
but on engine revolutions and engine operating
temperature. When the computer has calculated that the
oil needs changing, the GM Oil Life System
will
indicate that a change is necessary. The mileage between
oil and filter changes will vary depending on how you
drive your vehicle
-- usually between 3,000 miles
(5 000 km) and 7,500 miles (12 500 km) since your
last oil and filter change. Under severe conditions, the
system may come on before 3,000 miles (5 000 km).
Never drive your vehicle more than 7,500 miles
(12 500 km) or 12 months (whichever occurs first)
without an oil change.
The system won't detect dust in the oil. So, if you
drive in a dusty area, be sure to change your oil and
filter every 3,000 miles (5 000 km) or sooner.
Remember to reset the CHANGE OIL SOON light
whenever the oil is changed.How to Reset the GM Oil Life System

After changing the engine oil, the system must be reset.
With the ignition key in RUN but the engine off, fully
push and release the accelerator pedal slowly three times
within five seconds. If the CHANGE OIL SOON light
flashes, the system is resetting. Turn the key to OFF,
then start the vehicle. The oil life will change to 100%.
If the CHANGE OIL SOON light comes back on, the
system has not reset. Repeat the procedure.
What to Do with Used Oil
Did you know that used engine oil contains certain
elements that may be unhealthy for your skin and could
even cause cancer? Don't let used oil stay on your skin
for very long. Clean your skin and nails with soap and
water, or a good hand cleaner. Wash or properly throw
away clothing or rags containing used engine oil. (See
the manufacturer's warnings about the use and disposal
of oil products.)
Used oil can be a real threat to the environment. If you
change your own oil, be sure to drain all free
-flowing oil
from the filter before disposal. Don't ever dispose of oil by
putting it in the trash, pouring it on the ground, into
sewers, or into streams or bodies of water. Instead, recycle
it by taking it to a place that collects used oil. If you have
a problem properly disposing of your used oil, ask your
dealer, a service station or a local recycling center for help.

6-16
Engine Air Cleaner/Filter
The engine air cleaner/filter
is located underneath a
diagonal brace on the
driver's side of the engine.
To check or replace the air filter:
1. Loosen the wing nut on the air duct and lift up on the
two clips located on the top of the filter assembly.
2. Then disconnect the duct and reposition it while
removing the side cover.
3. Pull out the filter.
4. Replace the filter if needed.
5. Be sure to install the air filter and install the cover
tightly when you are finished.Refer to the Maintenance Schedule to determine when to
replace the air filter.
See ªScheduled Maintenance Servicesº in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can easily
get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.

6-17
Passenger Compartment Air Filter
The passenger compartment
air filter is located
underneath your hood just
below the windshield wiper
arm, on the passenger's side
(underneath the air inlet
grille) of the vehicle.
The filter traps most of the pollen from the air entering the air
conditioning module. Like your engine's air cleaner filter,
it may need to be changed periodically. For information
on how often to change the passenger compartment air
filter, see ªMaintenance Scheduleº in the Index.
To change the passenger compartment air filter, use the
following steps:
1. Turn off the ignition when the windshield wipers are
in the up position.
2. Raise the hood.3. Disconnect the windshield washer pump hose from
the fender rail and air inlet grille.
4. Reposition the hood weatherstrip from the
passenger's side of the vehicle (peel back halfway
to center).
5. Remove the air inlet grille retainers.
6. Remove the air inlet grille.
7. Remove the passenger compartment air filter.
8. Then replace the old air filter with the new one. For
the type of filter to use, see ªNormal Maintenance
Replacement Partsº in the Index.
9. Reposition the air inlet grille.
10. Reinstall the air inlet grille retainers.
11. Reposition the hood weatherstrip.

6-18
12. Reconnect the windshield washer pump hose to the
fender rail air inlet grille.
13. Close the hood.
14. Return the windshield wipers to the park position.
Automatic Transaxle Fluid
When to Check and Change
A good time to check your automatic transaxle fluid
level is when the engine oil is changed.
Change both the fluid and filter 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 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of
these conditions, change the fluid and filter at
100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transaxle. Too much can mean that some of the
fluid could come out and fall on hot engine parts
or exhaust system parts, starting a fire. Be sure
to get an accurate reading if you check your
transaxle fluid.

6-19
Wait at least 30 minutes before checking the transaxle
fluid level if you have been driving:

When outside temperatures are above 90F (32C).

At high speed for quite a while.

In heavy traffic
-- especially in hot weather.

While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180F to 200F
(82C to 93C).
Get the vehicle warmed up by driving about 15 miles (24 km)
when outside temperatures are above 50F (10C). If
it's colder than 50F (10C), you may have to drive longer.
Checking the Fluid Level
Prepare your vehicle as follows:

Park your vehicle on a level place. Keep the
engine running.

With the parking brake applied, place the shift lever
in PARK (P).

With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).

Let the engine run at idle for three to five minutes.Then, without shutting off the engine, follow these steps:
The automatic transaxle fluid dipstick is the red loop
located toward the rear of the engine. Pull out the
dipstick and wipe it with a clean rag or paper towel.
1. Push it back in all the way, wait three seconds and
then pull it back out again.

6-20
2. Check both sides of the dipstick, and read the
lower level. The fluid level must be in the
cross
-hatched area.
3. If the fluid level is in the acceptable range, push the
dipstick back in all the way.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transaxle fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.If the fluid level is low, add only enough of the proper
fluid to bring the level into the cross
-hatched area on
the dipstick.
1. Pull out the dipstick.
2. Using a long
-neck funnel, add enough fluid at the
dipstick hole to bring it to the proper level.
It doesn't take much fluid, generally less than
one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON
-III, because fluid with that label is
made especially for your automatic transaxle.
Damage caused by fluid other than
DEXRON

-III is not covered by your new
vehicle warranty.
3. After adding fluid, recheck the fluid level as
described under ªHow to Check.º
4. When the correct fluid level is obtained, push the
dipstick back in all the way.

6-21
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL
engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL
extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating or if you need to add coolant to your
radiator, see ªEngine Overheatingº in the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL
coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-22 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.