2003 BUICK CENTURY radiator

If the transaxle shift lever is in any position other
than FIRST (1) or SECOND (2) and the warning
light stays on after your parking brake is fully
released, it means there's a problem with the
system.
·If the traction control system is affected by an
engine-related problem, the system will turn off
and the warning light will come on.
When this warning light is on, the system will not limit
wheel spin. Adjust your driving accordingly.
Low Traction Light
If your vehicle has the
Enhanced Traction
System, this light will come
on when the system is
limiting wheel spin.
You may feel or hear the system working, but this is
normal. Slippery road conditions may exist if the low
traction light comes on, so adjust your driving
accordingly. The light will stay on for a few seconds after
the Enhanced Traction System stops limiting wheel spin.
See
Enhanced Traction System (ETS) on page 4-10.The low traction light also comes on brie¯y when you
turn the ignition key to RUN. If the light doesn't come on
then, have it ®xed so it will be there to tell you when
the Enhanced Traction System is active.
Engine Coolant Temperature
Warning Light
This light tells you that
your engine coolant has
overheated or your radiator
cooling fan is not working.
The light will come on brie¯y when your ignition is
turned on to show you that it is working.
If you have been operating your vehicle under normal
driving conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
See
Engine Overheating on page 5-26.
3-29

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-19
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-29
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-38
Brakes........................................................5-39Battery........................................................5-42
Jump Starting...............................................5-43
Headlamp Aiming...........................................5-49
Bulb Replacement..........................................5-51
Halogen Bulbs..............................................5-51
Headlamps..................................................5-51
Front Turn Signal and Parking Lamps..............5-52
Center High-Mounted Stoplamp (CHMSL).........5-53
Taillamps, Turn Signal, and Stoplamps............5-54
Back-Up Lamps............................................5-55
Replacement Bulbs.......................................5-55
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-57
In¯ation Ð Tire Pressure...............................5-57
Tire Pressure Monitor System.........................5-58
Tire Inspection and Rotation...........................5-60
When It Is Time for New Tires.......................5-61
Buying New Tires.........................................5-62
Uniform Tire Quality Grading..........................5-63
Wheel Alignment and Tire Balance..................5-64
Wheel Replacement......................................5-64
Tire Chains..................................................5-66
If a Tire Goes Flat........................................5-66
Changing a Flat Tire.....................................5-67
Compact Spare Tire......................................5-78
Section 5 Service and Appearance Care
5-1

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

Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended 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
Engine Overheating on page 5-26.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·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-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50,000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new vehicle
warranty.
5-23

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOLžcoolant 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 such as 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 ®re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
žcoolant.
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.
Checking Coolant
The engine coolant recovery tank is located on the
passenger's side of the vehicle at the rear of the engine
compartment. See
Engine Compartment Overview on
page 5-12for more information on location.
5-24

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.
Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat 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 ªHow to Add Coolant to the
Radiatorº later in this section.
{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 Ð even a
little Ð when the engine and radiator are hot.
{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
Cooling System on page 5-29.
5-25

Radiator Pressure Cap
Notice:Your radiator cap is a 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
over¯ow tube on the radiator ®ller neck.
The radiator pressure cap is located near the front of
the engine compartment on the passenger's side of the
vehicle. See
Engine Compartment Overview on
page 5-12for more information on location.
Engine Overheating
You will ®nd a coolant temperature gage and a hot
engine warning light on your instrument panel.
See
Engine Coolant Temperature Gage on page 3-30andEngine Coolant Temperature Warning Light on
page 3-29.
Overheated Engine Protection
Operating Mode
The emergency engine protection operating mode
allows your vehicle to be driven to a safe place in an
emergency situation. If an overheated engine condition
exists, this protection mode alternates ®ring groups
of cylinders to help prevent engine damage. In
this mode, you will notice a signi®cant loss in power and
engine performance. The engine coolant temperature
gage indicator will move to the red area, showing that an
overheated engine condition exists. Driving extended
miles (km) and/or towing a trailer in the overheated
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. See ªEngine Oilº in the Index.
5-26

Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Recovery Tank
B. Electric Engine Cooling Fan
C. Radiator Pressure Cap{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. Keep hands,
clothing and tools away from any underhood
electric fan.
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down. The vehicle
should be parked on a level surface.
5-29