2001 BUICK CENTURY check engine

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.
See ªEngine Compartment
Overviewº in the Index
for more information
on location.
To check or replace the engine air cleaner/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 engine air cleaner/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.

6-18
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 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.

6-22 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.

6-23 Checking Coolant
The engine coolant recovery tank is located on the
passenger's side of the vehicle at the back of the engine
compartment. See ªEngine Compartment Overviewº in
the Index for more information on location.
The vehicle must be on a
level surface. When your
engine is cold, the coolant
level should be at the
COLD mark or a little
higher. When your engine
is warm, the level should
be up to the HOT mark
or a little higher.
If this LOW COOLANT
light comes on and stays on,
it means you're low on
engine coolant.Adding Coolant
If you need more coolant, add the proper DEX
-COOL

coolant mixture at the coolant recovery tank, but be
careful not to spill it.
If the coolant recovery tank is completely empty, add
coolant to the radiator. See ªEngine Overheatingº in
the Index.
CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. With the coolant recovery tank, you will
almost never have to add coolant at the radiator.
Never turn the radiator pressure cap
-- even a
little
-- when the engine and radiator are hot.

6-24
CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
see ªCooling Systemº in the Index.
Radiator Pressure Cap
NOTICE:
Your radiator cap is a 15 psi (105 kPa)
pressure
-type cap and must be tightly installed to
prevent coolant loss and possible engine damage
from overheating. Be sure the arrows on the cap
line up with the overflow tube on the radiator
filler neck.
See ªEngine Compartment Overviewº in the Index for
more information on location.
Power Steering Fluid
The power steering fluid reservoir is located on the
passenger's side of the vehicle at the back of the engine
compartment. See ªEngine Compartment Overviewº in
the Index for more information on location.

6-25 When to Check Power Steering Fluid
It is not necessary to regularly check power steering
fluid unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at the fluid level on the dipstick.
The level should be at the FULL COLD mark.
If necessary, add only enough fluid to bring the
level up to the mark.
When the engine
compartment is hot,
the level should be at the
H mark. When it's cold,
the level should be at the
C mark. If the fluid is at
the ADD mark, you
should add fluid.
What to Use
To determine what kind of fluid to use, see
ªRecommended Fluids and Lubricantsº in the Index.
Always use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.

6-58
Vehicle Identification Number (VIN)
This is the legal identifier for your vehicle. It appears on
a plate in the front corner of the instrument panel, on
the driver's side. You can see it if you look through the
windshield from outside your vehicle. The VIN also
appears on the Vehicle Certification and Service Parts
labels and the certificates of title and registration.
Engine Identification
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specifications
and replacement parts.
Service Parts Identification Label
You'll find this label on the inside of the trunk lid.
It's very helpful if you ever need to order parts.
On this label is:

your VIN,

the model designation,
paint information and

a list of all production options and special equipment.
Be sure that this label is not removed from the vehicle.
Electrical System
Add-On Electrical Equipment
NOTICE:
Don't add anything electrical to your vehicle
unless you check with your dealer first. Some
electrical equipment can damage your vehicle
and the damage wouldn't be covered by your
warranty. Some add
-on electrical equipment
can keep other components from working as
they should.
Your vehicle has an air bag system. Before attempting
to add anything electrical to your vehicle, see ªServicing
Your Air Bag
-Equipped Vehicleº in the Index.