2001 CADILLAC DEVILLE engine

5-9
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your vehicle towed. See ªRoadside
Assistanceº and ªRecreational Vehicle Towingº 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 cluster. 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 the 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
CAUTION: (Continued)
CAUTION: (Continued)
surge tank pressure cap -- even a little -- they
can come 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.

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.

5-17
3. Then fill the coolant surge tank with the proper
mixture, to the base of the filler neck.4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fans.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches about 2.5 inches (6.4 cm)
below the base of the filler neck.