oil additives BUICK CENTURY 2003 Owner's Manual

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

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

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

E
Electrical System............................................5-88
Add-On Equipment......................................5-88
Fuses and Circuit Breakers...........................5-89
Headlamp Wiring.........................................5-88
Power Windows and Other Power Options......5-88
Windshield Wiper Fuses...............................5-88
Emergency Trunk Release Handle.....................2-14
Emissions Inspection and Maintenance
Programs...................................................3-33
Engine Coolant Level Check.............................6-10
Engine Cooling When Trailer Towing..................4-41
Engine Oil Additives........................................5-16
Engine Oil Level Check...................................6-10
Engine Oil Scheduled Maintenance..................... 6-5
Engine..........................................................5-18
Air Cleaner/Filter.........................................5-18
Battery.......................................................5-42
Change Engine Oil Light...............................3-35
Check and Service Engine Soon Light............3-31
Compartment Overview................................5-12
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-30
Coolant Temperature Warning Light................3-29
Coolant......................................................5-23
Cooling System Inspection............................6-14Engine (cont.)
Exhaust.....................................................2-30
Oil .............................................................5-13
Overheating................................................5-26
Starting......................................................2-20
Enhanced Traction System (ETS)......................4-10
Warning Light.............................................3-28
Entry Lighting.................................................3-14
Express-Down Window....................................2-16
Extender, Safety Belt.......................................1-29
Exterior Lamps...............................................3-11
F
Filter.............................................................5-18
Engine Air Cleaner......................................5-18
Finding a Station....................................3-40, 3-42
Finish Care....................................................5-83
Finish Damage...............................................5-84
Fixed Mast Antenna........................................3-52
Flash-to-Pass................................................... 3-7
Flat Tire, Changing.........................................5-67
Flat Tire........................................................5-66
Fluid.............................................................5-19
Automatic Transaxle.....................................5-19
Power Steering...........................................5-36
Windshield Washer......................................5-38
5