2005 BUICK CENTURY cooling

If the overheated engine warnings continue, there is
one more thing that can be done. Add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before this is done.
{CAUTION:
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly.
They are under pressure, and if you turn the
radiator pressure cap — even a little — they
can come out at high speed. Never turn the
cap when the cooling system, including the
radiator pressure cap, is hot. Wait for the
cooling system and radiator pressure cap to
cool if you ever have to turn the pressure cap.
How to Add Coolant to the Radiator
Notice:Your engine has a specic radiator ll
procedure. Failure to follow this procedure
could cause your engine to overheat and be
severely damaged.
Remove the radiator pressure cap when the cooling
system, including the radiator pressure cap and upper
radiator hose, is no longer hot.
1. Turn the pressure cap slowly counterclockwise to
its rst stop. Do not press down while turning the
pressure cap.
If a hiss is heard, wait for it to stop. A hiss means
there is still some pressure left.
5-30

8. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.9. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.
10. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the arrow on the pressure cap lines up properly.
11. Check the coolant in the recovery tank. The level in
the coolant recovery tank should be at the HOT
mark when the engine is hot or at the COLD mark
when the engine is cold.
5-33

Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
If you notice unusual tire wear or your vehicle pulling
one way or the other, the alignment may need to
be reset. If you notice your vehicle vibrating when
driving on a smooth road, your wheels may need to
be rebalanced.
Wheel Replacement
Replace any wheel that is bent, cracked or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle.
{CAUTION:
Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-70for
more information.
5-67

Underhood Fuse Block
Some fuses and relays are located in the underhood
fuse block on the passenger’s side of the vehicle in the
engine compartment. SeeEngine Compartment
Overview on page 5-12for more information on location.
Fuses Usage
1 Anti-Lock Brake System
2 Starter Solenoid
3 Power Seat, Rear Window Defogger
4High Blower, Hazard Flasher,
Stoplamps, Power Mirror,
Door Locks
Fuses Usage
5Ignition Switch, Stoplamps,
Anti-Lock Brake System, Turn
Signals, Cluster, Air Bag, Daytime
Running Lamps Module
6 Cooling Fan
7Retained Accessory Power,
Remote Keyless Entry, Data Link,
Heating, Ventilation, and Air
Conditioning Head; Cluster, Radio,
Cigarette Lighter
8Ignition Switch, Wipers, Audio
Steering Wheel Controls, Body
Control Module, Power Windows,
Sunroof, Heating, Ventilation, and
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)
5-94

Relays Usage
15 Not Used
16 Horn
17 Fog Lamps
18 Not Used
19 Fuel Pump
Fuses Usage
20 Not Used
21 Generator
22 Engine Control Module
23 Air Conditioner Compressor Clutch
24 Cooling Fan
25 Electronic Ignition
26 Transaxle
27 Horn
28 Fuel Injector
29 Oxygen Sensor
Fuses Usage
30 Engine Emissions
31 Fog Lamps
32 Right Headlamp
33 Rear Compartment Release
34 Parking Lamps
35 Fuel Pump
36 Left Headlamp
37 Not Used
38 Not Used
39 Not Used
40 Not Used
41 Not Used
42 Not Used
43 Not Used
§Air Conditioner Compressor
Clutch Diode
5-95

Capacities and Specications
The following approximate capacities are given in English and metric conversions.
Capacities and Specications
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134a 2.4 lbs 1.1 kg
Automatic Transaxle
Pan Removal and Replacement
After Complete Overhaul7.4 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 ft lb 140Y
All capacities are approximate. When adding, be sure to ll to the approximate level, as recommended in
this manual.
Engine Specications
Engine VIN Code Transaxle Spark Plug Gap
3100 V6 J Automatic .060 inches (1.52 cm)
5-96

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-13. Reset oil life system.
SeeEngine Oil Life System on page 5-16.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-18.An Emission Control Service. See footnote †.••
Rotate tires and check ination pressures and wear. SeeTires on page 5-53.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid
as needed.••
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transaxle uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
Inspect throttle system.See footnote (j).•
6-5

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(41 500)50,000
(83 000)75,000
(125 000)100,000
(166 000)125,000
(207 500)150,000
(240 000)
Replace spark plugs and inspect
spark plug wires.An Emission
Control Service.•
Engine cooling system service
(or every 5 years, whichever occurs
rst).An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.•
6-7