CADILLAC STS 2008 1.G Owners Manual

Engine Air Cleaner/Filter
The engine air cleaner/lter is in the engine
compartment on the driver’s side of the vehicle, near
the front. SeeEngine Compartment Overview on
page 5-11for more information on locating the air
cleaner/lter.
When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change after each
50,000 mile (80 000 km) interval. SeeScheduled
Maintenance on page 6-4for more information. If you
are driving in dusty/dirty conditions, inspect the lter
at each engine oil change.
How to Inspect the Engine
Air Cleaner/Filter
To inspect the air cleaner/lter remove the lter from
the vehicle and lightly shake the lter to release
loose dust and dirt. If the lter remains caked with dirt,
a new lter is required.
To inspect or replace the lter in the 3.6L V6 or
4.6L V8 engines, do the following:
1. Remove the two screws located on the top of
the cover.
2. Disconnect the coolant recovery hose so that it
is not going across the top of the engine air
cleaner/lter. 4.6L V8 Engine shown, 3.6L V6 Engine similar
5-23

3. Loosen the clamp and remove the duct from the
passenger’s side of the engine air cleaner/lter.
4. The two sides of the airbox are hinged at the
bottom. Open the airbox by pushing the top of
the airbox cover toward the engine.
5. Remove the air lter by lifting it straight up through
the opening in the airbox.
6. Inspect or replace the engine air cleaner/lter. See
Normal Maintenance Replacement Parts on
page 6-15for the correct part number for the lter.
7. Reinstall the cover by reversing Steps 1 through 4.
If your vehicle has the 4.4L V8 STS-V engine, there
is a special procedure for checking and changing the air
cleaner/lter. Because this procedure is difficult, you
should have this done at the dealership service
department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-15.
{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned.
The air cleaner not only cleans the air; it helps
to stop ames if the engine backres. If it is
not there and the engine backres, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
5-24

Automatic Transmission Fluid
How to Check Automatic
Transmission Fluid
It is not necessary to check the transmission uid level.
A transmission uid leak is the only reason for uid
loss. If a leak occurs, take the vehicle to the
dealer/retailer service department and have it repaired
as soon as possible.
There is a special procedure for checking and changing
the transmission uid. Because this procedure is
difficult, you should have this done at the dealership
service department. Contact your dealer for additional
information or the procedure can be found in the service
manual. To purchase a service manual, seeService
Publications Ordering Information on page 7-15.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the uid listed inRecommended Fluids and
Lubricants on page 6-13.
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 5-29.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give 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 the rst maintenance
service after each 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.
5-25

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 once or twice a
year, have your dealer check your cooling system.
Notice:If you use extra inhibitors and/or additives
in your vehicle’s cooling system, you could
damage your vehicle. 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.
5-26

Checking Coolant
The coolant surge tank and pressure cap are located on
the driver’s side of the vehicle, toward the rear of the
engine compartment. SeeEngine Compartment
Overview on page 5-11for more information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD/FROID line on the side of the surge tank.
Follow the arrow from the top of the tank down the
side to the horizontal mark.
5-27

Checking Intercooler System Coolant
(4.4L V8 STS-V Engine Only)
SeeEngine Compartment Overview on page 5-11for
the location of the intercooler system pressure cap.Notice:This vehicle has a specic coolant ll
procedure. Failure to follow this procedure could
cause your engine to overheat and be severely
damaged.
Park the vehicle on a level surface and turn off the
engine. When the engine is cold, the coolant level
should be visible in the intercooler ll neck.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the intercooler ll neck, but only
when the engine is cool. SeeCooling System on
page 5-32for instructions on how to add coolant to the
intercooler ll neck.
5-28

{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 a pressure cap, make sure it is
hand-tight and fully seated.
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 5-11for more
information on location.
Engine Overheating
There are two engine hot messages that could be
displayed in the Driver Information Center (DIC).
SeeDIC Warnings and Messages on page 3-80for
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 3-67andEngine Coolant
Temperature Warning Light on page 3-66for more
information.
5-29

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. 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 the vehicles 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 5-31for 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 5-31for
information on driving to a safe place in an
emergency.
If No Steam Is Coming From
Your Engine
An overheat warning, can indicate a serious problem.
If you get an engine overheat warning but see or
hear no steam, the problem might 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.
5-30

If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the climate controls to the highest heat setting
and fan speed and open the windows, as
necessary.
If the coolant warning light is not on or the coolant
temperature gage does not indicate the engine
is overheating, you can drive. Just to be safe, drive
slower for about 10 minutes. If the warnings do not come
back on, drive normally.
If the warnings continue and you have not stopped, pull
over, stop, and park the vehicle right away.
If there is still no sign of steam, idle the engine for three
minutes while parked. If the warnings are still indicated,
turn off the engine and get everyone out of the
vehicle until it cools down. Also, see “Overheated
Engine Protection Operating Mode” later in this section.
You might decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
This operating mode allows your vehicle to be driven
to a safe place in an emergency. Should an overheated
engine condition exist, an overheat protection mode
which alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a loss
in power and engine performance. An engine overheat
warning will indicate that an overheat condition
exists. Driving extended miles (km) and/or 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 and change the oil.
SeeEngine Oil on page 5-18.
5-31

Cooling System
When you decide it is safe to lift the hood, this is what
you will see:
A. Engine Cooling Fans
B. Coolant Surge Tank and Pressure CapSome vehicles may have an engine driven fan, as well
as the electric pusher fans which are located behind
the vehicle’s grille.
{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,
do not do anything else until it cools down. The vehicle
should be parked on a level surface.
When the engine is cold, the coolant level should be at
or slightly above the FULL COLD/FROID line on the
side of the coolant surge tank. If it is not, you may have
a leak at the pressure cap or in the radiator hoses,
heater hoses, radiator, water pump, or somewhere else
in the cooling system. 3.6L V6 Engine shown, 4.6L V8 and 4.4L V8 STS-V
Engines similar
5-32