2003 BUICK CENTURY engine oil

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

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

How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the COLD mark, add a 50/50 mixture ofclean,
drinkable waterand DEX-COOLžengine coolant at
the coolant recovery tank. SeeEngine Coolant on
page 5-23for more information.
{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:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts. Use
the recommended coolant and the proper coolant
mixture.
{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.
When the coolant in the coolant recovery tank is at the
COLD mark, start your vehicle.
5-31

When your brake ¯uid falls to a low level, your brake
warning light will come on. SeeBrake System Warning
Light on page 3-27.
What to Add
When you do need brake ¯uid, use only DOT-3 brake
¯uid. Use new brake ¯uid from a sealed container
only. See
Part D: Recommended Fluids and Lubricants
on page 6-16.
Always clean the brake ¯uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of ¯uid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake ¯uid.
Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they'll have to be replaced.
Don't let someone put in the wrong kind of ¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
ªAppearance Careº in the Index. United States
Canada
5-40

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

Normal Maintenance
Replacement Parts
Normal Maintenance Replacement Parts
Part Number
Engine Air Cleaner/Filter A1614C*
Engine Oil Filter Type PF47*
Passenger Compartment Air Filter 10406026
Spark PlugsType 41±101*
Gap: 0.060 inches (1.52 mm)
Wiper Blade
Type
LengthSheperd's Hook
22.0 inches (56.0 cm)
*ACDelco
žpart number.
5-95