fuel BUICK CENTURY 2003 Owner's Guide

When you put the fuel cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make
sure you fully install the cap. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. This would allow fuel to evaporate into the
atmosphere. See
Malfunction Indicator Lamp on
page 3-31.
{CAUTION:
If a ®re starts while you're refueling, don't
remove the nozzle. Shut off the ¯ow of fuel by
shutting off the pump or by notifying the
station attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer can get one for you.
If you get the wrong type, it may not ®t properly.
This may cause your malfunction indicator lamp to
light and may damage your fuel tank and emissions
system. See ªMalfunction Indicator Lampº in the
Index.
Filling a Portable Fuel Container
{CAUTION:
Never ®ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
·Dispense gasoline only into approved
containers.
·Do not ®ll a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed or
on any surface other than the ground.
·Bring the ®ll nozzle in contact with the
inside of the ®ll opening before operating
the nozzle. Contact should be maintained
until the ®lling is complete.
·Don't smoke while pumping gasoline.
5-9

Checking Things Under the
Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing and tools away
from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a ®re. These include liquids like fuel,
oil, coolant, brake ¯uid, windshield washer and
other ¯uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

A. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-38.
B. Battery. See
Battery on page 5-42.
C. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-89.
D. Remote Positive (+) Battery Terminal. See
Jump
Starting on page 5-43.
E. Radiator Pressure Cap. See
Radiator Pressure Cap
on page 5-26.
F. Engine Coolant Recovery Tank. See
Engine Coolant
on page 5-23.
G. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-36.
H. Electric Engine Cooling Fan. See
Jump Starting on
page 5-43.
I. Engine Oil Fill Cap. See
Engine Oil on page 5-13.
J. Engine Oil Dipstick. See
Engine Oil on page 5-13.
K. Automatic Transaxle Fluid Dipstick. See
Automatic
Transaxle Fluid on page 5-19.
L. Brake Fluid Reservoir. See
Brakes on page 5-39.
M. Engine Air Cleaner/Filter. See
Engine Air
Cleaner/Filter on page 5-18.
Engine Oil
Checking Engine Oil
It's 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 the yellow loop
located near the front
of the engine. See
Engine
Compartment Overview
on page 5-12
for more
information on location.
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.
5-13

As in the chart shown previously, SAE 5W-30 is the
only viscosity grade recommended for your vehicle. You
should look for and use only oils which have the API
Starburst symbol and which are also identi®ed as
SAE 5W-30. If you cannot ®nd such SAE 5W-30 oils,
you can use an SAE 10W-30 oil which has the API
Starburst symbol, if it's going to be 0ÉF (-18ÉC)
or above. Do not use other viscosity grade oils, such as
SAE 10W-40 or SAE 20W-50 under any conditions.
Notice:Use only engine oil with the American
Petroleum Institute Certi®ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
žoil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below-20ÉF (-29ÉC), 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
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
(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

Headlamp Aiming
Your vehicle has a headlamp system equipped with
horizontal and vertical aim indicators. The aim has been
pre-set at the factory and should need no further
adjustment. This is true even though your vertical and
horizontal aim indicators may not fall exactly on the
ª0º (zero) marks on their scales.
If your vehicle is damaged in an accident, the headlamp
aim may be affected. Aim adjustment may be necessary
if it is difficult to see lane markers (for horizontal
aim), or if oncoming drivers ¯ash their high beams at
you (for vertical aim). If you believe your headlamps
need to be re-aimed, we recommend that you take it to
your dealer for service; however, it is possible for
you to re-aim your headlamps as described in the
following procedure.
Notice:To make sure your headlamps are aimed
properly, read all the instructions before beginning.
Failure to follow these instructions could cause
damage to headlamp parts.To check the aim, the vehicle should be properly
prepared as follows:
·The headlamps must be off for one hour prior to
aiming and must remain off during this procedure.
·The vehicle must have all four tires on a perfectly
level surface.
·If necessary, pads may be used on an uneven
surface.
·The vehicle should not have any snow, ice or mud
attached to it.
·The vehicle should be fully assembled and all other
work stopped while headlamp aiming is being done.
·There should not be any cargo or loading of the
vehicle, except it should have a full tank of fuel and
one person or 160 lbs (75 kg) on the driver's seat.
·Close all doors.
·Tires should be properly in¯ated.
·Rock the vehicle to stabilize the suspension.
5-49

Notice:Don't let anyone tell you that underin¯ation
or overin¯ation is all right. It's not. If your tires
don't have enough air (underin¯ation), you can get
the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Don't forget your compact spare tire. It should be at
60 psi (420 kPa).
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Pressure Monitor System
If your vehicle has the tire in¯ation monitor system, it
can alert you to a large change in the pressure of
one tire. The system ªlearnsº the pressure at each tire
throughout the operating speed range of your vehicle.
The system normally takes between 45 and 90 minutes
of driving to learn the tire pressures. This time may
be longer depending on your individual driving habits.
Learning need not be accumulated during a single
trip. Once learned, the system will remember the tire
pressures until the system is recalibrated.
After the system has learned tire pressures with properly
in¯ated tires, the LOW TIRE light will come on if the
pressure in one tire becomes 12 psi (83 kPa) lower than
the other three tires. The tire in¯ation monitor system
won't alert you if the pressure in more than one tire is low,
if the system is not properly calibrated, or if the vehicle is
moving faster than 70 mph (110 km/h).
5-58

Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, accelerated corrosion (rust) can occur on
the underbody parts such as fuel lines, frame, ¯oor pan
and exhaust system even though they have corrosion
protection.
At least every spring, ¯ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being ¯ushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage
can take two forms: blotchy, ring-shaped discolorations,
and small, irregular dark spots etched into the paint
surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs ®rst.
Vehicle Care/Appearance Materials
See your GM dealer for more information on purchasing
the following products.
Vehicle Care/Appearance Materials
Description Usage
Polishing Cloth
Wax-TreatedInterior and exterior
polishing cloth.
Tar and Road Oil
RemoverRemoves tar, road oil and
asphalt.
Chrome Cleaner and
PolishUse on chrome or
stainless steel.
White Sidewall Tire
CleanerRemoves soil and black
marks from whitewalls.
Vinyl CleanerCleans vinyl tops,
upholstery and
convertible tops.
Glass CleanerRemoves dirt, grime,
smoke and ®ngerprints.
Chrome and Wire Wheel
CleanerRemoves dirt and grime
from chrome wheels and
wire wheel covers.
5-85

Fuses Usage
4High Blower, Hazard Flasher,
Stoplamps, Power Mirror, Door
Locks
5Ignition Switch, BTSI, Stoplamps,
Anti-Lock Brake System, Turn
Signals, Cluster, Air Bag, Daytime
Running Lamps Module
6 Cooling Fan
7Retained Accessory Power, Keyless
Entry, Data Link, Heating Ventilation
Air Conditioning Head, Cluster,
Radio, Cigarette Lighter
8Ignition Switch, Wipers, Radio,
Steering Wheel Controls, Body
Control Module, Power Windows,
Sunroof, Heating Ventilation Air
Conditioning Controls, Daytime
Running Lamps, Rear Window
Defogger Relay
Relays Usage
9 Cooling Fan 2
10 Cooling Fan 3
11 Starter Solenoid
12 Cooling Fan 1
13 Ignition Main
14 Air Pump (Optional)
15 Not Used
16 Horn
17 Fog Lamps
18 Not Used
19 Fuel Pump
5-92

Fuses Usage
20 Not Used
21 Generator
22 Engine Control Module
23 A/C Compressor Clutch
24 Cooling Fan
25 Electronic Ignition
26 Transaxle
27 Horn
28 Fuel Injector
29 Oxygen Sensor
30 Engine Emissions
31 Fog Lamps
Fuses Usage
32 Headlamp (Right)
33 Rear Compartment Release
34 Parking Lamps
35 Fuel Pump
36 Headlamp (Left)
37 Not Used
38 Not Used
39 Not Used
40 Not Used
41 Not Used
42 Not Used
43 Not Used
SYMBOL A/C Compressor Clutch Diode
5-93

Capacities and Speci®cations
Capacities and Speci®cations
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134a 2.4 lbs 1,1 kg
Automatic Transaxle
Pan Removal and Replacement
After Complete Overhaul
When draining/replacing converter, more ¯uid will be
needed.7.4 quarts
10.0 quarts7,0 L
9,5 L
Cooling System Including Reservoir 11.7 quarts 11,0 L
Engine Oil with Filter 4.0 quarts 3,8 L
Fuel Tank 17.0 gallons 64,0 L
Wheel Nut Torque 100 lb ft 140Y
All capacities are approximate. When adding, be sure to ®ll to the approximate level, as recommended in this
manual. See
Part D: Recommended Fluids and Lubricants on page 6-16.
Engine Speci®cations
Engine VIN Code Displacement Firing Order
3100 V6J
1191 CID 1±2±3±4±5±6
5-94