2000 BUICK CENTURY cooling

5-17 How to Add Coolant to the Radiator
NOTICE:
Your engine has a specific radiator fill procedure.
Failure to follow this procedure could cause your
engine to overheat and be severely damaged.
1. You can remove the
radiator pressure cap
when the cooling
system, including the
radiator pressure cap
and upper radiator
hose, is no longer hot.
Turn the pressure cap slowly counterclockwise until it
first stops. (Don't press down while turning the
pressure cap.) If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure left.
2. Then keep turning the
pressure cap, but now
push down as you
turn it. Remove the
pressure cap.
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.

5-19
6. Then fill the coolant recovery tank to the COLD
mark on the coolant recovery tank.
7. Put the cap back on the coolant recovery tank, but
leave the pressure cap off.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
filler neck may be lower. If the level is lower, add
more of the proper DEX
-COOL
coolant mixture
through the filler neck until the level reaches the
base of the filler neck.

6-21
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL
engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL
extended 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 ªEngine Overheatingº in the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL
coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

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
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-22 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant 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 like 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 fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
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.

6-24
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
ªCooling Systemº in the Index.
Radiator Pressure Cap
NOTICE:
Your radiator cap is a 15 psi (105 kPa)
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 overflow tube on the radiator
filler neck.
Power Steering Fluid

6-48
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.
See ªChanging a Flat Tireº in the Index for
more information.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used or
how far it's been driven. It could fail suddenly
and cause an accident. If you have to replace a
wheel, use a new GM original equipment wheel.
Tire Chains
NOTICE:
Use tire chains only where legal and only when
you must. Use only SAE Class ªSº type chains
that are the proper size for your tires. Install
them on the front tires and tighten them as
tightly as possible with the ends securely
fastened. Drive slowly and follow the chain
manufacturer's instructions. If you can hear the
chains contacting your vehicle, stop and retighten
them. If the contact continues, slow down until it
stops. Driving too fast or spinning the wheels
with chains on will damage your vehicle.

6-61
Underhood Electrical Center -- Passenger's Side
Some fuses and relays are located in the underhood
electrical center on the passenger's side of the engine
compartment.Maxi fuse Description
1 ABS
2 Starter Solenoid
3 Power Seats, Rear Defog
4 High Blower, Hazard Flasher,
Stoplamps, Power Mirror,
Door Locks
5 Ignition Switch, BTSI, Stoplamps,
ABS, Turn Signals, Cluster,
Air Bag, DRL Module
6 Cooling Fan
7 Interior Lamps, Retained
Accessory Power, Keyless Entry,
Data Link, HVAC Head, Cluster,
Radio, AUX Power (Power Drop),
Cigarette Lighter
8 Ignition Switch, Wipers, Radio,
Steering Wheel Controls, Body
Control Module, AUX Power
(Power Drop), Power Windows,
Sunroof, HVAC Controls, DRL,
Rear Defog Relay

6-62
Mini relay Description
9 Cooling Fan 2
10 Cooling Fan 3
11 Starter Solenoid
12 Cooling Fan 1
13 Ignition Main
14 Air Pump (Optional)
Micro
relay Description
15 A/C Clutch
16 Horn
17 Not Used
18 Not Used
19 Fuel Pump
Mini fuse Description
20 Air Pump (Optional)
21 Generator
22 ECM
23 A/C Compressor Clutch
24 Cooling Fan
25 Electronic Ignition
26 TransaxleMini relay Description
27 Horn
28 Fuel Injector
29 Oxygen Sensor
30 Engine Emissions
31 Not Used
32 Headlamp (Right)
33 Rear Compartment Release
34 Parking Lamps
35 Fuel Pump
36 Headlamp (Left)
37 Spare
38 Spare
39 Spare
40 Spare
41 Spare
42 Spare
43 Fuse Puller
SYMBOL A/C Compressor Clutch Diode