BUICK LESABRE 2002 Owner's Manual

5-10
Engine Overheating
You will find a warning light about a hot engine as well
as an engine coolant temperature gage on your vehicle's
instrument panel cluster. If your vehicle is equipped
with the optional Driver Information Center (DIC),
an ENGINE COOLANT LOW warning will appear
on the display.
If Steam Is Coming From Your Engine
CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before you
open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not
be covered by your warranty.

5-11 If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.

Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (
)
or THIRD (3).If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for about
10 minutes. If the warning doesn't come back on,
you can drive normally.
If the warning continues, pull over, stop, and park
your vehicle right away.
If there's still no sign of steam, idle the engine for
three minutes while you're parked. If you still have
the warning, turn off the engine and get everyone
out of the vehicle until it cools down.
You may decide not to lift the hood but to get service
help right away.

5-12
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Electric Engine Cooling Fans
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.
See ªEngine Compartment
Overviewº in the Index
for more information
on location.

5-13
The coolant level should be at or above the FULL
COLD mark (if the engine is hot, the coolant level
should be at FULL HOT). If it isn't, you may have a
leak at the pressure cap or in the radiator hoses, heater
hoses, radiator, water pump or somewhere else in the
cooling system.
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them. If you
do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
If there seems to be no leak, with the engine on, check
to see if the electric engine cooling fans are running.
If the engine is overheating, both fans should be
running. If they aren't, your vehicle needs service.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
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.

5-14 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 FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX
-COOL
engine
coolant at the coolant recovery tank. See ªEngine
Coolantº in the Index for 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 fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
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.

5-15
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
FULL COLD mark, start your vehicle.
If the overheat warning continues, there's one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.
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.
CAUTION: (Continued)
CAUTION: (Continued)
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.

5-16 How to Add Coolant to the Radiator
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.
3. Remove the 3800 Series II V6 engine cover shield to
access the bleed valve.

5-17
A. Clean the area around the engine oil fill tube and cap
before removing. Twist the oil fill tube, with cap
attached, counterclockwise and remove it.
B. If you have the supercharged engine, remove the nut
in the center of the cover shield.
C. Lift the engine cover shield at the front, slide the
catch tab out of the engine bracket and remove the
cover shield.
D. Put the oil fill tube, with cap attached, in the valve
cover oil fill hole until you're ready to replace the
cover shield.
There is one
bleed valve. It is
located on the
thermostat housing.
4. After the engine cools, open the coolant air
bleed valve.

5-18
5. Fill the radiator with the proper DEX-COOL

coolant mixture, up to the base of the filler neck.
See ªEngine Coolantº in the Index for more
information about the proper coolant mixture.
If you see a stream of coolant coming from an
air bleed valve, close the valve. Otherwise, close
the valve after the radiator is filled.
6. Rinse or wipe any spilled coolant from the engine
and the compartment.7. Replace the 3800 Series II V6 engine cover shield.
A. Remove the oil fill tube, with cap attached, from
the valve cover.
B. Insert the catch tab on the cover shield under the
bracket on the engine.
C. Place the hole in the cover shield over the hole in
the valve cover. Install oil fill tube and cap by
twisting clockwise.
D. If you have the supercharged engine, install the
nut in the center of the cover shield.
8. Then fill the coolant
recovery tank to the
FULL COLD mark.
9. Put the cap back on the coolant recovery tank,
but leave the radiator pressure cap off.

5-19
10. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.
11. 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.
12. Then replace the
presure cap. At any time
during this procedure if
coolant begins to flow
out of the filler neck,
reinstall the pressure
cap. Be sure the arrow
on the pressure cap lines
up like this.