2000 CADILLAC DEVILLE engine coolant

3-5
DEFROST: Press this button to quickly remove
fog or frost from the windshield. This setting sends most
of the airflow to the windshield with only a small
amount to the floor outlets.
FAN SPEEDS: Press the AUTO. At this setting,
the fan speed is automatically controlled. If it is cold
outside, the blower may not run in the maximum high
fan speed right away. The system checks the
temperature of the engine coolant to assure it is warm
enough to provide heat. When the engine coolant is
warm, the controller allows the fan to gradually increase
to a higher speed. This prevents cold air from blowing
into the passenger compartment.
OFF: Press the knob to turn the system off. Fresh
air will continue to flow through the vehicle, and the
system will try to maintain the previously set
temperature. The outside temperature will show on
the display when the system is OFF.AC: Press this button to turn the air conditioning on and
off. The system will cool and dehumidify the air inside
the vehicle. In the AUTO mode the air conditioning
compressor only operates when the system determines it
is needed. The display will show A/C OFF when the air
conditioning is off.
RECIRCULATION: Press this button to limit the
amount of fresh air entering your vehicle. This is helpful
when you are trying to cool the air quickly or limit odors
entering your vehicle. In the AUTO mode, the system
will use recirculation as necessary to cool the air.
Pressing the recirculation button will change the
operation to a manual mode and the air will recirculate
non
-stop. Press this button again to turn off the
recirculation feature.
If you notice the windows fogging, press the
recirculation button to exit the recirculation mode.

5-9
NOTICE:
Use the proper towing equipment to avoid
damage to the bumper, fascia or fog lamp areas
of the vehicle.
With current trends in automotive styles and design, it is
essential that the correct towing equipment is used to
tow a vehicle. Your vehicle can be towed with wheel lift
or car carrier equipment.
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº in the Index.
Engine Overheating
You will find an ENGINE COOLANT HOT, IDLE
ENGINE message or an ENGINE OVERHEATED,
STOP ENGINE message on the Driver Information
Center (DIC). You will also hear a chime. There is also
an engine temperature warning light and/or gage on the
instrument panel. See ªEngine Coolant Temperature
Warning Lightº or ªEngine Coolant Temperature Gageº
in the Index.
Overheated Engine Protection
Operating Mode
Should an overheated engine condition exist and the
message ENGINE OVERHEATED, STOP ENGINE is
displayed, an overheat protection mode which alternates
firing groups of cylinders helps prevent engine damage.
In this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle
to be driven to a safe place in an emergency; you may
drive up to 50 miles (80 km). Towing a trailer in the
overheat protection mode should be avoided.
NOTICE:
After driving in the overheated engine protection
operating mode, to avoid engine damage, allow
the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair
the cause of coolant loss, change the oil and
reset the oil life indicator. See ªEngine Oilº in
the Index.

5-10 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. See ªOverheated Engine
Protection Operating Modeº in the Index.

5-11
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. See ªOverheated
Engine Protection Operating Modeº in the Index.
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. Dial temperature control to the highest heat setting
and open the windows, as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) 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. Also, see ªOverheated
Engine Protection Operating Modeº listed previously in
this section.
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 Surge Tank with Pressure Cap
B. 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 surge tank is boiling,
don't do anything else until it cools down.

5-13
A low coolant level should be indicated by a CHECK
COOLANT LEVEL message on the Driver Information
Center. If it is, you may have a leak 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.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.
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
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.
How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, but the coolant level
isn't at the proper level (2.5 inches (6.4 cm) below the
base of the fill neck), add a 50/50 mixture of clean,
drinkable water and DEX
-COOL
coolant at the
coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is cool
before you do it. (See ªEngine Coolantº in the Index for
more information.)
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 coolant surge
tank pressure cap
-- even a little -- they can come
CAUTION: (Continued)
CAUTION: (Continued)
out at high speed. Never turn the cap when the
cooling system, including the coolant surge tank
pressure cap, is hot. Wait for the cooling system
and coolant surge tank pressure cap to cool if you
ever have to turn the pressure cap.
CAUTION: (Continued)

5-15
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:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts. So
use the recommended coolant.
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.