2005 CADILLAC DEVILLE engine overheat

Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle may need a
different turn signal asher and/or extra wiring. Check
with your dealer. The arrows on your instrument
panel will ash whenever you signal a turn or lane
change. Properly hooked up, the trailer lamps will also
ash, telling other drivers you are about to turn,
change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It
is important to check occasionally to be sure the trailer
bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you do not shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
On long uphill grades, reduce speed to 45 to 50 mph
(70 to 90 km/h) and avoid prolonged use of SECOND (2)
gear and engine speeds above 3800 rpm.Climbing grades steeper than four percent at
temperatures above 90°F (32°C) with a loaded vehicle
and trailer is not recommended. The cooling system
may temporarily overheat. SeeEngine Overheating on
page 5-27.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
4-42

But if you ever have to park your rig on a hill, here is
how to do it:
1. Apply your regular brakes, but do not shift into
PARK (P).
2. Have someone place chocks behind the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then shift into
PARK (P) rmly and apply your parking brake.
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine,
Shift into a gear, and
Make sure the parking brake has released.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you are
pulling a trailer. See the Maintenance Schedule for
more on this. Things that are especially important in
trailer operation are automatic transaxle uid (do
not overll), engine oil, drive belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If you
are trailering, it is a good idea to review this information
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
Your cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-27.
4-43

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling the Tank..............................................5-7
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-14
Engine Oil Life System..................................5-17
Engine Air Cleaner/Filter................................5-19
Automatic Transaxle Fluid..............................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Overheated Engine Protection
Operating Mode........................................5-29
Cooling System............................................5-30
Power Steering Fluid.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-42
Headlamp Aiming...........................................5-48
Headlamp Horizontal Aiming...........................5-49
Headlamp Vertical Aiming..............................5-50
Bulb Replacement..........................................5-51
Halogen Bulbs..............................................5-51
Headlamps..................................................5-51
Front Turn Signal, Sidemarker, Parking and
Cornering Lamps.......................................5-55
Replacement Bulbs.......................................5-56
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-57
Tire Sidewall Labelling...................................5-58
Tire Terminology and Denitions.....................5-62
Ination - Tire Pressure.................................5-65
Tire Pressure Monitor Operation.....................5-68
Tire Inspection and Rotation...........................5-69
When It Is Time for New Tires.......................5-70
Buying New Tires.........................................5-71
Uniform Tire Quality Grading..........................5-72
Wheel Alignment and Tire Balance..................5-73
Wheel Replacement......................................5-73
Tire Chains..................................................5-75
Section 5 Service and Appearance Care
5-1

Automatic Transaxle Fluid
When to Check and Change Automatic
Transaxle Fluid
A good time to check your automatic transaxle uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transaxle uid listed inRecommended
Fluids and Lubricants on page 6-12.
How to Check Automatic
Transaxle Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.Notice:Too much or too little uid can damage the
transaxle. Too much can mean that some of the uid
could come out and fall on hot engine or exhaust
system parts, starting a re. Too little uid could
cause the transaxle to overheat. Be sure to get an
accurate reading if you check the transaxle uid.
Wait at least 30 minutes before checking the transaxle
uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it is colder than 50°F (10°C), you may have to
drive longer.
5-21

How to Reset the Transaxle Fluid
Indicator
After the transaxle uid has been changed, the transaxle
uid change indicator must be reset. To reset the
indicator, do the following:
1. Press the INFO (Information) button on the Driver
Information Center (DIC) until TRANS FLUID LIFE
is displayed.
2. Press and hold the RESET button until 100% is
displayed. This resets the transaxle uid change
indicator.
The percentage of transaxle uid life remaining may be
checked at any time by pressing INFO on the DIC
until the TRANS FLUID LIFE message appears.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, 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, seeEngine Overheating on
page 5-27.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Giving freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-24

What to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{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 would not get the overheat warning.
Your engine could catch re 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 would not 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 two times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
5-25

Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the coolant surge tank, but only
when the engine is cool.
{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. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure the arrow
lines up with the tube.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may occur.
Be sure the cap is properly and tightly secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
Engine Overheating
You will nd an ENGINE COOLANT HOT, IDLE
ENGINE message or an ENGINE OVERHEATED,
STOP ENGINE message displayed in the Driver
Information Center (DIC). SeeDIC Warnings and
Messages on page 3-60for more information. You will
also hear a chime.
There is also an engine temperature warning light
and/or gage on the instrument panel cluster. SeeEngine
Coolant Temperature Warning Light on page 3-49and
Engine Coolant Temperature Gage on page 3-49.
5-27

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 re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the
vehicle until the engine is cool.
SeeOverheated Engine Protection Operating
Mode on page 5-29for information on driving
to a safe place in an emergency.Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. SeeOverheated Engine
Protection Operating Mode on page 5-29for
information on driving to a safe place in an
emergency.
If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem.
If you get an engine overheat warning with no low
coolant message, 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.
5-28