2009 CADILLAC STS cooling

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

After you have removed the sight shields (if equipped) on the 3.6L V6 engine, here is what you will see:
A. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
B. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
C. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
D. Battery. SeeBattery on page 5-42.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
F. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
J. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
L. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
5-13

After you have removed the sight shields (if equipped) on the 4.6L V8 engine, here is what you will see:
A. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
C. Battery. SeeBattery on page 5-42.
D. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
E. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.
G. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.H. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
I. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
J. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
K. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
L. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
5-15

After you have removed the sight shields (if equipped) on the 4.4L V8 STS-V engine, here is what you will see:
A. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-124.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
C. Remote Negative (-) Terminal. SeeJump Starting on
page 5-42.
D. Battery. SeeBattery on page 5-42.
E. Passenger Compartment Air Filter. SeePassenger
Compartment Air Filter on page 3-54.
F. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-38.
G. Intercooler System Pressure Cap. SeeEngine
Coolant on page 5-27.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.I. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-18.
J. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-18.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-39.
L. Engine Coolant Surge Tank and Pressure Cap.
SeeCoolant Surge Tank Pressure Cap on page 5-34
andCooling System on page 5-26.
M. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
If your vehicle is equipped with front compartment
underhood sight shields, before closing the hood be
sure to reinstall the sight shields. To reinstall the shields,
locate the tabs on the left and right sides and insert them
into the openings in the tower to tower brace. Then insert
the fasteners into the top of the shield and push the
fasteners back into place.
5-17

Cooling System
The cooling system allows the engine to maintain the
correct working temperature.
A. Electric Engine Cooling Fan(s) (Out of view)
B. Mechanical Engine Cooling Fan (If equipped)
(Out of view)
C. Coolant Surge Tank and Pressure Cap{CAUTION:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
CAUTION: (Continued)
3.6L V6 Engine shown, 4.6L V8 and
4.4L V8 STS-V Engines similar
5-26

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