2002 BUICK CENTURY Owner's Manual

6-15
How to Reset the CHANGE OIL SOON Light
The GM Oil Life System
calculates when to change
your engine oil and filter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation
occurs where you change your oil prior to a CHANGE
OIL SOON light being turned on, reset the system.
After changing the engine oil, reset the system by
performing the following steps:
1. With the engine off, turn the ignition key to RUN.
2. Fully push and release the accelerator pedal slowly
three times within five seconds.
If the CHANGE OIL SOON light flashes, the
system is resetting.
3. Turn the key to OFF, then start the vehicle.
The oil life will change to 100 percent.
If the CHANGE OIL SOON light comes back on,
the system has not reset. Repeat the procedure.What to Do with Used Oil
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 threat to the environment. If you
change your own oil, be sure to drain all the oil from
the filter before disposal. Never 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 in the engine compartment on the driver's
side of the vehicle. See ªEngine Compartment Overviewº
in the Index for more information on location.
To check or replace the engine air cleaner/filter,
do the following:
1. Loosen the wing nut on the air duct.
2. Lift up on the two clips
located on the top of the
filter assembly.3. Then disconnect the duct and reposition it while
removing the side cover.
4. Pull out the filter.
5. Replace the filter if needed.
6. Be sure to reinstall the 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.

6-17
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.
Passenger Compartment Air Filter
The passenger compartment
air filter is located
underneath your hood
below the windshield wiper
arm, on the passenger's side
(below 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. Remove the hood weatherstrip from the passenger's
side of the vehicle (peel back halfway to center).
5. Remove the three air inlet grille retainers.
6. Remove the air inlet grille.

6-18
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. Reinstall the air inlet grille.
10. Reinstall the air inlet grille retainers.
11. Reattach the hood weatherstrip.
12. Reconnect the windshield washer pump hose to the
fender rail and 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.

6-19 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. Too little
fluid could cause the transaxle to overheat. Be
sure to get an accurate reading if you check your
transaxle fluid.
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.

6-20
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 handle is the red
loop located toward the rear of the engine. See ªEngine
Compartment Overviewº in the Index for more
information on location.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.

6-21
3. Check both sides of the dipstick, and read the
lower level. The fluid level must be in the
cross
-hatched area.
4. 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.

6-22
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.