engine BUICK CENTURY 2004 Service Manual

Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
If You Are Stuck: In Sand, Mud, Ice
or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you do not want to
spin your wheels too fast. The method known as
“rocking” can help you get out when you are stuck, but
you must use caution.
{CAUTION:
If you let your tires spin at high speed, they
can explode, and you or others could be
injured. And, the transaxle or other parts of the
vehicle can overheat. That could cause an
engine compartment re or other damage.
When you are stuck, spin the wheels as little
as possible. Do not spin the wheels above
35 mph (55 km/h) as shown on the
speedometer.
Notice:Spinning your wheels can destroy parts of
your vehicle as well as the tires. If you spin the
wheels too fast while shifting your transaxle back
and forth, you can destroy your transaxle. See
“Rocking Your Vehicle To Get It Out.”
For information about using tire chains on your vehicle,
seeTire Chains on page 5-73.
4-30

Trailering means changes in handling, acceleration,
braking, durability, and fuel economy. Successful, safe
trailering takes correct equipment, and it has to be
used properly.
That is the reason for this part. In it are many
time-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before pulling a trailer.
Load-pulling components such as the engine, transaxle,
wheel assembly, and tires are forced to work harder
against the drag of the added weight. The engine
is required to operate at relatively higher speeds and
under greater loads, generating extra heat. What
is more, the trailer adds considerably to wind resistance,
increasing the pulling requirements.
If You Do Decide To Pull A Trailer
Here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you will be driving. A good source
for this information can be state or provincial police.
Consider using a sway control. Ask a hitch
dealer about sway controls.
Do not tow a trailer at all during the rst 1,000 miles
(1 600 km) the vehicle is driven. The engine, axle or
other parts could be damaged.
Then, during the rst 500 miles (800 km) that the
vehicle tows a trailer, do not drive over 50 mph
(80 km/h) and do not make starts at full throttle.
This helps the engine and other parts of the vehicle
wear in at the heavier loads.
Obey speed limit restrictions when towing a trailer.
Do not drive faster than the maximum posted
speed for trailers, or no more than 55 mph
(90 km/h), to save wear on the vehicle’s parts.
There are three important considerations have to do
with weight:
The weight of the trailer.
The weight of the trailer tongue.
The total weight on the vehicle’s tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than 1,000 lbs (450 kg).
But even that can be too heavy.
4-40

Total Weight on Your Vehicle’s Tires
Be sure the vehicle’s tires are inated to the upper limit
for cold tires. These numbers can be found on the
Tire-Loading Information label. SeeLoading Your
Vehicle on page 4-34. Be sure not to go over the GVW
limit for the vehicle, or the GAWR, including the
weight of the trailer tongue. If a weight distribution hitch
is used, make sure not to go over the rear axle limit
before applying the weight distribution spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why the right hitch is needed. Here
are some rules to follow:
The rear bumper on the vehicle is not intended
for hitches. Do not attach rental hitches or
other bumper-type hitches to it. Use only a
frame-mounted hitch that does not attach to
the bumper.
If holes need to be made in the body of the vehicle
to install a trailer hitch, then be sure to seal the holes
later when the hitch is removed. If the holes are not
sealed, deadly carbon monoxide (CO) from the
exhaust can get into the vehicle. SeeEngine Exhaust
on page 2-29. Dirt and water can, too.
Safety Chains
Chains should always be attached between the vehicle
and the trailer. Cross the safety chains under the
tongue of the trailer so that the tongue will not drop to
the road if it becomes separated from the hitch.
Instructions about safety chains may be provided by the
hitch manufacturer or by the trailer manufacturer.
Follow the manufacturer’s recommendation for attaching
safety chains and do not attach them to the bumper.
Always leave just enough slack so the rig can be turned.
And, never allow safety chains to drag on the ground.
Trailer Brakes
Because the vehicle has anti-lock brakes, do not try to
tap into the vehicle’s brake system. If that is done,
both brake systems will not work well, or at all.
Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, get to know the
rig. Acquaint yourself with the feel of handling and
braking with the added weight of the trailer. And always
keep in mind that the vehicle is now a good deal
longer and not nearly as responsive as the vehicle is
by itself.
4-42

Turn Signals When Towing a Trailer
When towing a trailer, the vehicle may need a different
turn signal asher and/or extra wiring. Check with
your dealer. The arrows on the instrument panel will
ash whenever signaling a turn or lane change.
Properly hooked up, the trailer lamps will also ash,
telling other drivers you are about to turn, change lanes
or stop.
When towing a trailer, the arrows on the instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. You may think drivers behind you
are seeing your signal when they are not. It is important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long hill or steep downgrade. If the vehicle
is not shifted down, the brakes might have to be
used so much that they would get hot and no longer
work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of engine and transaxle overheating.
If towing a trailer, you may want to drive in THIRD (3)
instead of AUTOMATIC OVERDRIVE (
X). Shift
to a lower gear as needed.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if the rig ever has to be parked on a hill, here is
how to do it:
1. Apply the regular brakes, but do not shift into
PARK (P) yet.
2. Have someone place chocks under the trailer’s
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply the parking
brake, and shift to PARK (P).
5. Release the regular brakes.
4-44

When You Are Ready to Leave After
Parking on a Hill
1. Apply the regular brakes and hold the pedal down
while you:
Start the engine.
Shift into a gear.
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle will need service more often when it pulls a
trailer. See.Scheduled Maintenance on page 6-4for
more information. Things that are especially important in
trailer operation are automatic transaxle uid; which
should not be overlled; engine oil, drive belt, cooling
system, and brake system. Each of these is covered
in this manual, and the Index will help you nd
them quickly. If trailering, it is a good idea to review this
information before starting on a trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-25.
4-45

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transaxle Fluid..............................5-19
Engine Coolant.............................................5-22
Radiator Pressure Cap..................................5-25
Engine Overheating.......................................5-25
Cooling System............................................5-28
Power Steering Fluid.....................................5-35
Windshield Washer Fluid................................5-36
Brakes........................................................5-38Battery........................................................5-41
Jump Starting...............................................5-42
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
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-57
Ination - Tire Pressure.................................5-64
Tire Pressure Monitor System.........................5-65
Tire Inspection and Rotation...........................5-67
When It Is Time for New Tires.......................5-68
Buying New Tires.........................................5-69
Uniform Tire Quality Grading..........................5-70
Wheel Alignment and Tire Balance..................5-71
Wheel Replacement......................................5-72
Tire Chains..................................................5-73
If a Tire Goes Flat........................................5-74
Changing a Flat Tire.....................................5-75
Compact Spare Tire......................................5-87
Section 5 Service and Appearance Care
5-1

CAUTION: (Continued)

Be sure to use the proper nuts, bolts and
other fasteners. “English” and “metric”
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle
can affect the airow around it. This may cause
wind noise and affect windshield washer performance.
Check with your dealer before adding equipment to
the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
of 87 or higher. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you might damage
your engine. A little pinging noise when you accelerate
or drive uphill is considered normal. This does not
indicate a problem exists or that a higher-octane fuel is
necessary. If you are using 87 octane or higher-octane
fuel and hear heavy knocking, your engine needs
service.
5-4

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems due
to dirty injectors or valves, try a different brand of
gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specications described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-6

Filling Your Tank
{CAUTION:
Fuel vapor burns violently and a fuel re can
cause bad injuries. To help avoid injuries to
you and others, read and follow all the
instructions on the pump island. Turn off your
engine when you are refueling. Do not smoke
if you are near fuel or refueling your vehicle.
Keep sparks, ames and smoking materials
away from fuel. Do not leave the fuel pump
unattended when refueling your vehicle — this
is against the law in some places. Keep
children away from the fuel pump; never let
children pump fuel.
Turn the vehicle off to refuel.The tethered fuel cap is located behind a hinged door
on the driver’s side of the vehicle. To remove the
fuel cap, turn it slowly counterclockwise. The fuel cap
has a spring in it; so if it is released too soon, it will
spring back.
5-7

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.
Hood Release
To open the hood, do the following:
1. Pull the interior hood
release handle located
below the instrument
panel, to the left of the
steering column.
5-10