2018 CADILLAC XTS engine

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
242 VEHICLE CARE
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty.
Viscosity Grade
Use SAE 5W-30 viscosity grade
engine oil.
Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below −29 °C
(−20 °F), an SAE 0W-30 oil may be
used. An oil of this viscosity grade will
provide easier cold starting for the
engine at extremely low temperatures.
When selecting an oil of the
appropriate viscosity grade, it is
recommended to select an oil of the
correct specification. See
“Specification ”earlier in this section.
Engine Oil Additives/Engine Oil
Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for
good performance and engine
protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your own
oil, be sure to drain all the oil from
the filter before disposal. Never dispose of oil by putting it in the trash
or pouring it on the ground, into
sewers, or into streams or bodies of
water. Recycle it by taking it to a place
that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based on a
combination of factors which include
engine revolutions, engine
temperature, and miles driven. Based
on driving conditions, the mileage at
which an oil change is indicated can
vary considerably. For the oil life
system to work properly, the system
must be reset every time the oil is
changed.
When the system has calculated that
oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the
oil as soon as possible within the next
1 000 km (600 mi). It is possible that,
if driving under the best conditions,

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
VEHICLE CARE 243
the oil life system might indicate that
an oil change is not necessary for up
to a year. The engine oil and filter
must be changed at least once a year
and at this time the system must be
reset. Your dealer has trained service
people who will perform this work and
reset the system. It is also important
to check the oil regularly over the
course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally,
the oil must be changed at 5 000 km
(3,000 mi) since the last oil change.
Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
Reset the system whenever the engine
oil is changed so that the system can
calculate the next engine oil change.
To reset the system:1. Using the DIC buttons, display REMAINING OIL LIFE on the
DIC. See Driver Information Center
(DIC) 0136. 2. Press and hold SEL to clear the
CHANGE ENGINE OIL SOON
message and reset the oil life
at 100%.
Be careful not to reset the oil life
display accidentally at any time
other than after the oil is
changed. It cannot be reset
accurately until the next oil
change.
The oil life system can also be reset as
follows: 1. Display REMAINING OIL LIFE on the DIC. See Driver Information
Center (DIC) 0136.
2. Fully press and release the accelerator pedal three times
within five seconds.
If the CHANGE ENGINE OIL
SOON message is not on, the
system is reset.
The system is reset when the
CHANGE ENGINE OIL SOON message
is off. If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat the
procedure.
Automatic Transmission
Fluid
A transmission fluid leak is the only
reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and
have it repaired as soon as possible.
See your dealer to have the fluid and
filter changed at the intervals listed in
the
Maintenance Schedule 0317.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0236.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/filter,
see Maintenance Schedule 0317.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
244 VEHICLE CARE
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/filter,
make sure that the engine air cleaner/
filter housing and nearby components
are free of dirt and debris. Remove the
engine air cleaner/filter. Lightly tap
and shake the engine air cleaner/filter
(away from the vehicle), to release
dust and dirt. Inspect the engine air
cleaner/filter for damage, and replace
if damaged. Do not clean the engine
air cleaner/filter or components with
water or compressed air.To inspect or replace the engine air
cleaner/filter:
3.6L V6 Engine
1. Remove the seven screws on top of the engine air cleaner/filter
housing.
2. Lift the air cleaner/filter cover housing away from the engine.
3. Pull out the filter.
4. Inspect or replace the engine air cleaner/filter.
5. Reverse Steps 1–3 to reinstall the filter cover housing.
3.6L V6 Twin Turbo Engine

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
VEHICLE CARE 245
1. Screws
2. Secondary Air Hose
3. Lower Air Duct Clamp
4. Lower Electrical Connector
5. Upper Electrical Connector
6. Upper Air Duct Clamp
1. Disconnect the lower and upperoutlet ducts by loosening the
lower (3) and upper (6) air duct
clamps.
2. Disconnect the lower (4) and upper (5) electrical connectors
and wiring attachments from the
air cleaner/filter cover.
3. Remove the screws (1) on top of the air cleaner/filter cover.
4. Lift the air cleaner/filter cover housing away from the engine.
5. Pull out the air cleaner/filter.
6. Inspect or replace the engine air cleaner/filter.
7. Reverse Steps 1–5 to reinstall the air cleaner/filter cover housing.
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. The air cleaner
not only cleans the air; it helps to
stop flames if the engine backfires.
Use caution when working on the
engine and do not drive with the air
cleaner/filter off.
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always have
the air cleaner/filter in place when
driving.
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
3.6L V6 Engine
1. Electric Engine Cooling Fans
(Out of View)
2. Coolant Surge Tank and Pressure Cap

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
246 VEHICLE CARE
3.6L V6 Twin Turbo Engine
1. Electric Engine Cooling Fans(Out of View)
2. Charged Air Coolant (CAC) Bottle and Pressure Cap
3. Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan 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.
{Warning
Do not touch heater or radiator
hoses, or other engine parts. They
can be very hot and can burn you.
Do not run the engine if there is a
leak; all coolant could leak out.
That could cause an engine fire and
can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The engine and Charged Air Coolant
(CAC) cooling systems in the vehicle
are filled with DEX-COOL engine
coolant mixture.
See Recommended Fluids and
Lubricants 0326 and Maintenance
Schedule 0317.
The following explains the cooling
systems and how to check and add
coolant when it is low. If there is a
problem with engine overheating, see
Engine Overheating 0249.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down to
−37 °C (−34 °F), outside
temperature.
. Gives boiling protection up to 129
°C (265 °F), engine temperature.
. Protects against rust and
corrosion.
. Will not damage aluminum parts.
. Helps keep the proper engine
temperature.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
VEHICLE CARE 247
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard GMW3420 and
clean, drinkable water. Anything
else can cause damage to the
engine cooling system and the
vehicle, which would not be covered
by the vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or pouring into sewers,
streams, or bodies of water. Have the
coolant changed by an authorized
service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant
The vehicle must be on a level surface
when checking the coolant level.
The engine coolant surge tank and
CAC bottle are in the engine
compartment on the driver side of the
vehicle. See Engine Compartment
Overview 0236.
Check to see if coolant is visible in the
surge tank and CAC bottle. If the
coolant inside the surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible but
the coolant level is not at or above the
mark pointed to on the surge tank or
at the CAC bottle cold fill mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant.
Be sure the cooling system is cool
before this is done. If no coolant is visible in the coolant
surge tank or CAC bottle, add coolant
as follows:
How to Add Coolant to the
Surge Tank
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
248 VEHICLE CARE
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
The coolant surge tank pressure cap
can be removed when the cooling
system, including the surge tank
pressure cap and upper radiator hose,
is no longer hot.
1. Turn the pressure cap slowly counterclockwise. If a hiss is
heard, wait for that to stop.
A hiss means there is still some
pressure left.
2. Keep turning the pressure cap slowly and remove it. 3. Fill the coolant surge tank with
the proper mixture to the mark
pointed to on the front 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. 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 mark pointed to on the front
of the coolant surge tank.
5. Replace the pressure cap tightly.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–5.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the cap
is properly and tightly secured.
How to Add Coolant to the CAC
Bottle
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.

Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-11354412) -
2018 - crc - 11/16/17
VEHICLE CARE 249
The CAC bottle pressure cap can be
removed when the Charged Air
Coolant cooling system, including the
CAC bottle pressure cap, is no
longer hot.
1. Turn the pressure cap slowlycounterclockwise and remove it.
2. Fill the CAC bottle with the proper mixture to the cold fill
mark pointed to on the front of
the CAC bottle.
3. Replace the pressure cap tightly.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the cap
is properly and tightly secured.
Engine Overheating
The vehicle has an engine coolant
temperature gauge and an engine
temperature light to warn of engine
overheating.
There are also engine hot messages
that may display in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when one of these warnings
appears, but get service help right
away. See Roadside Service 0338.
If the decision is made to lift the
hood, make sure the vehicle is parked
on a level surface.
Then check to see if the engine
cooling fans are running. If the engine
is overheating, the fans should be
running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.