2009 CADILLAC STS engine overheat

Repeat this until help arrives but only when you feel
really uncomfortable from the cold. Moving about
to keep warm also helps.
If it takes some time for help to arrive, now and then
when you run the engine, push the accelerator pedal
slightly so the engine runs faster than the idle speed.
This keeps the battery charged to restart the vehicle and
to signal for help with the headlamps. Do this as little as
possible to save fuel.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow.
SeeRocking Your Vehicle to Get It Out on page 4-24.
If the vehicle has a traction system, it can often help
to free a stuck vehicle. Refer to the vehicle’s traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high speed,
they can explode, and you or others could be
injured. The vehicle can overheat, causing an
engine compartment re or other damage. Spin
the wheels as little as possible and avoid going
above 35 mph (55 km/h) as shown on the
speedometer.
For information about using tire chains on the vehicle,
seeTire Chains on page 5-81.
4-23

Turn Signals When Towing a Trailer
The arrows on the instrument panel ash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also ash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument
panel ash for turns even if the bulbs on the trailer
are burned out. For this reason you may think other
drivers are seeing the signal when they are not.
It is important to check occasionally to be sure the
trailer bulbs are still working.
The vehicle has bulb warning lights. When a trailer
lighting system is plugged into the vehicle’s lighting
system, its bulb warning lights may not let you know if
one of the lamps goes out. So, when the trailer lighting
system is plugged in, be sure to check the vehicle and
trailer lamps from time to time to be sure they are all
working. Once the trailer lamps are disconnected, the
bulb warning lights again can tell you if one of the vehicle
lamps is out.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce the
vehicle’s speed to around 45 mph (70 km/h) to reduce
the possibility of the engine and the transmission
overheating.
Vehicles can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the automatic
transmission in P (Park) for a few minutes before turning
the engine off. If the overheat warning comes on, see
Engine Overheating on page 5-34.
4-37

Parking on Hills
{CAUTION:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on a
at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park)
yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
Start the engine
Shift into a gear
Release the parking brake
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
The vehicle needs service more often when pulling a
trailer. See this manual’s Maintenance Schedule
or Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily overheat during
severe operating conditions. SeeEngine Overheating on
page 5-34.
4-38

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements......5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
the Vehicle.................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
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...................................................5-18
Engine Oil Life System..................................5-21
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-25
Cooling System............................................5-26
Engine Coolant.............................................5-27
Coolant Surge Tank Pressure Cap..................5-34
Engine Overheating.......................................5-34Overheated Engine Protection
Operating Mode........................................5-36
Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-42
All-Wheel Drive..............................................5-47
Rear Axle.......................................................5-48
Front Axle......................................................5-49
Headlamp Aiming...........................................5-50
Bulb Replacement..........................................5-51
High Intensity Discharge (HID) Lighting............5-51
Halogen Bulbs..............................................5-51
Back-Up Lamps............................................5-52
Replacement Bulbs.......................................5-52
Windshield Replacement.................................5-52
Windshield Wiper Blade Replacement..............5-52
Tires..............................................................5-54
Winter Tires.................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-59
Run-Flat Tires (STS-V)..................................5-62
Ination - Tire Pressure.................................5-64
High-Speed Operation...................................5-65
Tire Pressure Monitor System.........................5-66
Tire Pressure Monitor Operation.....................5-68
Section 5 Service and Appearance Care
5-1

CAUTION: (Continued)
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine re, and you could be burned.
Get any leak xed before you drive the vehicle.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant
in the vehicle.
Engine Coolant
The cooling system in the vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst.
The following explains the cooling system and how to
check and add coolant when it is low. If there is a problem
with engine overheating, seeEngine Overheating on
page 5-34.
5-27

What to Use
{CAUTION:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could get
too hot but you would not get the overheat
warning. The engine could catch re and you or
others could be burned. Use a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant.Use a 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant. If using this mixture, nothing else
needs to be added. This mixture:
Gives freezing protection down to−34°F (−37°C),
outside temperature.
Gives boiling protection up to 265°F (129°C),
engine temperature.
Protects against rust and corrosion.
Will not damage aluminum parts.
Helps keep the proper engine temperature.
Notice:If an improper coolant mixture is used,
the engine could overheat and be badly damaged.
The repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and
other parts.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 6-13for more information.
5-28

Checking Intercooler System Coolant
(4.4L V8 STS-V Engine Only)
The vehicle must be on a level surface when checking
the coolant level.
SeeEngine Compartment Overview on page 5-12for
the location of the intercooler system pressure cap.
Turn off the engine. When the engine is cold, the coolant
level should be visible in the intercooler ll neck.
How to Add Coolant to the Surge Tank
{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.
Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure could
cause the engine to overheat and be severely
damaged.
5-30

3. Add the proper DEX-COOL®coolant mixture to the
ll neck, until the coolant reaches the COLD FILL
line on the ll neck.
With the Intercooler System pressure cap off, start
the engine and let it run for a couple of minutes.
Then turn the engine off. By this time, the coolant
level inside the ll neck may be lower. If the level
drops to where coolant is no longer visible in the
horizontal tube section of the ll neck, with the engine
off add more of the DEX-COOL
®coolant mixture
to the ll neck until the level is again visible in the
horizontal tube section.
4. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
If the coolant is not at the proper level when the system
cools down again, see your dealer.
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.
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
The vehicle has several indicators to warn of engine
overheating.
There are two engine hot messages that could be
displayed in the Driver Information Center (DIC).
SeeDIC Warnings and Messages on page 3-79
DIC Warnings and Messages for more information.
If the engine is overheating, then you will nd a coolant
temperature gage and a coolant warning light on the
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-65andEngine Coolant Temperature
Warning Light on page 3-64for more information.
5-34