2006 CADILLAC STS engine coolant

3. Fill the coolant surge tank with the proper
DEX-COOL®coolant mixture, to slightly above the
FULL COLD/FROID line on the side of the
coolant surge tank.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. The upper radiator hose is
the largest of the hoses which comes out of the
radiator, on the passenger’s side of the vehicle.
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 the FULL COLD/FROID
line on the side of the coolant surge tank.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Start the engine and allow it to warm up. If the CHECK
COOLANT LEVEL message does not appear on the
Driver Information Center (DIC), the coolant is at
the proper ll level. If the CHECK COOLANT LEVEL
message does appear, repeat Steps 1 to 3 then reinstall
the pressure cap, or see your GM dealer.
5-36

How to Add Coolant to the
Intercooler System Fill Neck
(4.4L V8 STS-V Engine Only)
If you have not found a problem yet, turn the engine off
and allow it to cool down, then check to see if coolant is
visible within the horizontal tube section of the ll neck.
If coolant is not visible, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant to the ll neck.
Be sure the Intercooler System, including the Intercooler
System pressure cap, is cool before doing so. See
Engine Coolant on page 5-26for more information.
{CAUTION:
Turning the Intercooler System pressure cap
when the engine and intercooler are hot can
allow steam and scalding liquids to blow out
and burn you badly. Never turn the Intercooler
System pressure cap, even a little, when the
engine and intercooler are hot.
{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:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
5-37

{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.
1. You can remove the Intercooler System pressure
cap when the Intercooler System, including the
upper intercooler hoses, are no longer hot.Turn the pressure cap slowly counterclockwise
about one-quarter of a turn. If you hear a hiss, wait
for that to stop. This will allow any pressure still
left to be vented.
2. Then keep turning the pressure cap slowly, and
remove it.
3. Add the proper DEX-COOL
®coolant mixture to the
ll neck, until the coolant reaches the COLD FILL
line on the ll neck.
4. 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.
5. 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.
5-38

Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure to read
the manufacturer’s instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use a uid that has sufficient
protection against freezing.
Adding Washer Fluid
The CHECK WASHER FLUID message will appear
on the Driver Information Center (DIC) when the uid
level is low. SeeDIC Warnings and Messages on
page 3-79for more information.
Open the cap with the
washer symbol on it. Add
washer uid until the
tank is full. SeeEngine
Compartment Overview on
page 5-12for reservoir
location.Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions for
adding water.
Do not mix water with ready-to-use washer uid.
Water can cause the solution to freeze and
damage your washer uid tank and other parts
of the washer system. Also, water does not
clean as well as washer uid.
Fill your washer uid tank only three-quarters
full when it is very cold. This allows for
expansion if freezing occurs, which could
damage the tank if it is completely full.
Do not use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
5-40

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-18. Reset oil life system.
SeeEngine Oil Life System on page 5-22.An Emission Control Service.••
Visually check for any leaks or damage.See footnote (k).••
Inspect engine air cleaner lter. If necessary, replace lter. SeeEngine Air
Cleaner/Filter on page 5-24.See footnote (m).•
Check tires for ination pressures and wear. SeeTires on page 5-56. If tire
rotation is recommended for your vehicle, rotate tires. SeeTire Inspection and
Rotation on page 5-70and “Tire Wear Inspection” inAt Least Once a Month
on page 6-9.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels. If you have the 4.4L V8
supercharged engine, check intercooler uid level. Add uid as needed.••
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
Replace passenger compartment air lter.See footnote (g).•
6-5

(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors, and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken airbag
coverings, and have them repaired or replaced.
The airbag system does not need regular maintenance.
(f)Lubricate all key lock cylinders. Lubricate all
hinges and latches, including those for the hood, rear
compartment, glove box door, and console door.
More frequent lubrication may be required when
exposed to a corrosive environment. Applying silicone
grease on weatherstrips with a clean cloth will make
them last longer, seal better, and not stick or squeak.
(g)If you drive regularly under dusty conditions, the lter
may require replacement more often.
(h)Change automatic transmission uid and lter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as limousine service.
Uses such as high performance operation.(j)Drain, ush, and rell cooling system. This service
can be complex; you should have your dealer perform
this service. See Engine Coolant on page 5-26 for
what to use. Inspect hoses. Clean radiator, condenser,
pressure cap, and ller neck. Pressure test the
cooling system and pressure cap.
(k)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired
and the uid level checked. Add uid if needed.
(l)Inspect throttle body bore and valve plates for
deposits. Open the throttle valve and inspect all
surfaces. Clean as required.
(m)If you drive regularly under dusty conditions,
inspect the lter at each engine oil change.
(n)Visually inspect belt for fraying, excessive cracks,
or obvious damage. Replace belt if necessary.
Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability, and emission control performance of your
vehicle. Your GM Goodwrench
®dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-12.
6-8

At Each Fuel Fill
It is important to perform these underhood checks at
each fuel ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-18for further
details.
Notice:It is important to check your oil regularly
and keep it at the proper level. Failure to keep your
engine oil at the proper level can cause damage
to your engine not covered by your warranty.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-26for further details.
Intercooler Coolant Level Check
(4.4L Supercharged Engine)
Check the coolant level and add DEX-COOL®coolant
mixture if necessary. SeeEngine Coolant on page 5-26
for further details.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the
windshield washer uid reservoir and add the proper
uid if necessary.
At Least Once a Month
Tire Ination Check
Visually inspect your vehicle’s tires and make sure they
are inated to the correct pressures. Do not forget to
check the spare tire. SeeTires on page 5-56for further
details. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire (STS Only) on
page 5-83.
Tire Wear Inspection
Tire rotation is recommended if your vehicle has the
same size tires at all four wheel positions and may
be required for high mileage highway drivers prior to
the Engine Oil Life System service notication. Check
the tires for wear and, if necessary, rotate the tires.
SeeTire Inspection and Rotation on page 5-70.
6-9

Recommended Fluids and
Lubricants
Fluids and lubricants identied below by name, part
number, or specication may be obtained from
your dealer.
Usage Fluid/Lubricant
Engine OilThe engine requires a special engine
oil meeting GM Standard GM4718M.
Oils meeting this standard may be
identied as synthetic, and should
also be identied with the American
Petroleum Institute (API) Certied
for Gasoline Engines starburst
symbol. However, not all synthetic
API oils with the starburst symbol
will meet this GM standard. You
should look for and use only oil that
meets GM Standard GM4718M.
GM Goodwrench
®oil meets all the
requirements for your vehicle. For the
proper viscosity, seeEngine Oil on
page 5-18.
Engine Cooling
System50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant on
page 5-26.
Usage Fluid/Lubricant
Intercooler
System
(4.4L V8
Supercharged
engine)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake uid.
Windshield
WasherGM Optikleen
®Washer Solvent.
Parking Brake
Cable GuidesChassis Lubricant
(GM Part No. U.S. 12377985, in
Canada 88901242) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Power Steering
SystemGM Power Steering Fluid
(GM Part No. U.S. 89021184,
in Canada 89021186).
Automatic
Transmission
(6-Speed)DEXRON
®-VI Automatic
Transmission Fluid.
Automatic
Transmission
(5-Speed)DEXRON
®-III Automatic
Transmission Fluid. Look for
“Approved for the H-Specication”
on the label.
6-12