CADILLAC CT6 2019 Owner's Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
300 VEHICLE CARE
Follow these guidelines:
.To get an accurate reading, park
the vehicle on level ground. Check
the engine oil level after the
engine has been off for at least
two hours. Checking the engine oil
level on steep grades or too soon
after engine shutoff can result in
incorrect readings. Accuracy
improves when checking a cold
engine prior to starting. Remove
the dipstick and check the level.
. If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the
engine is not warm. Pull out the
dipstick, wipe it with a clean paper
towel or cloth, then push it back
in all the way. Remove it again,
keeping the tip down, and check
the level.When to Add Engine Oil
2.0L L4 Turbo (LSY) and 4.2L V8 Twin
Turbo (LTA) Engines
3.0L V6 Twin Turbo (LGW) and 3.6L V6 (LGX) Engines
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use.
For engine oil crankcase capacity, see
Capacities and Specifications 0397.
Caution
Do not add too much oil. Oil levels
above or below the acceptable
operating range shown on the
dipstick are harmful to the engine.
If the oil level is above the
operating range (i.e., the engine has
so much oil that the oil level gets
above the cross-hatched area that
shows the proper operating range),
the engine could be damaged. Drain
the excess oil or limit driving of the
vehicle, and seek a service
professional to remove the
excess oil.
See Engine Compartment Overview
0 292 for the location of the engine oil
fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.

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Selecting the Right Engine Oil
(Except 4.2L V8 Twin Turbo
(LTA) Engine)
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. SeeRecommended
Fluids and Lubricants 0392.
Specification
Use full synthetic engine oils that
meet the dexos1 specification. Engine
oils that have been approved by GM
as meeting the dexos1 specification
are marked with the dexos1 approved
logo. See www.gmdexos.com.
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty. Viscosity Grade
Except the 2.0L L4 Turbo (LSY)
engine, 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.
For the 2.0L L4 Turbo (LSY) engine,
use SAE 0W-20 viscosity grade
engine oil.
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.
Selecting the Right Engine Oil
(4.2L V8 Twin Turbo (LTA)
Engine)
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. See Recommended
Fluids and Lubricants 0392. Specification
Use engine oils that meet the dexos2
specification.
Engine oils that have been approved
by GM as meeting the dexos2
specification are marked with the
dexos2 approved logo.
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 0W-40 viscosity grade
engine oil.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
302 VEHICLE CARE
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 dexos
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,
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
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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) 0150.
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. Using the DIC buttons, display REMAINING OIL LIFE on the
DIC. See Driver Information Center
(DIC) 0150. 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
How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
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. The vehicle is not equipped with a
transmission fluid level dipstick.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at the dealer. Contact your dealer
for additional information.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty.
Always use the correct automatic
transmission fluid. See
Recommended Fluids and Lubricants
0
392.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule 0383, and be sure to use the
fluid listed in Recommended Fluids and
Lubricants 0392.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
304 VEHICLE CARE
Engine Air Filter Life
System
If equipped, this feature provides an
indication of when to change the
engine air filter. It is based on driving
conditions, which can cause when to
change to vary greatly. It is possible
an air filter change may not be
indicated for up to four years.
When to Change Engine Air
Filter
Replace the engine air filter when the
REPLACE NOW message displays on
the Driver Information Center (DIC).
This should be done as soon as
possible within the next 1 000 km
(600 mi) or at the next oil change,
depending on the DIC message. The
system must be reset after the engine
air filter is changed. See your dealer
for service and to reset the system.
When a REPLACE AT NEXT OIL
CHANGE message displays, this
indicates that the engine air filter
change is necessary at the next engine
oil change.
How to Reset Engine Air Filter
Life System
Reset the system whenever the engine
air filter is replaced so that the system
can calculate the next engine air filter
change.
To reset:1. Place the vehicle in P (Park).
2. Select Engine Air Filter Life on the DIC menu. See Driver
Information Center (DIC) 0150.
3. Press
Tto move to the Reset/
Disable display area. Select Reset
then press SEL. Then press Yes
to confirm the reset.
4. 100% Air Filter Life will be displayed when the Engine Air
Filter Life System is successfully
reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment. See Engine
Compartment Overview 0292.
When to Inspect the Engine Air
Cleaner/Filter
.
For intervals on changing and
inspecting the engine air filter, see
Maintenance Schedule 0383.
. If equipped with Engine Air Filter
Life System, see Engine Air Filter
Life System 0304.
. If driving in very dusty areas,
follow the engine air filter
inspecting and changing intervals,
see Maintenance Schedule 0383.
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
loose dust and dirt. Inspect the engine
air cleaner/filter for damage, and
replace if damaged. Do not clean the

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
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engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:
2.0L L4 Engine
1. Remove the six screws on top of the engine air cleaner/filter cover.
2. Lift and slide the engine air cleaner/filter cover open.
3. Lift and remove the engine air cleaner/filter.
4. Inspect or replace the engine air cleaner/filter. 5. Reverse Steps 1–3 to reinstall the
engine air cleaner/filter cover.
3.0L V6 Engine
1. Remove the 10 screws on top of the engine air cleaner/filter cover
to gain access to both air
cleaners/filters.
2. Lift the engine air cleaner/filter cover open on the hinge.
3. Lift and remove one or both engine air cleaner(s)/filter(s).
4. Inspect or replace one or both engine air cleaner(s)/filter(s).
5. Reverse Steps 1–3 to reinstall the engine air cleaner/filter cover.
3.6L V6 Engine
1. Screws (6)
2. Bolts (3)
3. Diagonal Brace
1. Remove the three bolts (2) andthe diagonal brace (3).
2. Remove the six screws (1) on top of the engine air cleaner/filter
cover.
3. Lift the engine air cleaner/filter cover open on the hinge.
4. Lift and remove the engine air cleaner/filter.
5. Inspect or replace the engine air cleaner/filter.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
306 VEHICLE CARE
6. Reverse Steps 1–4 to reinstall theengine air cleaner/filter cover
and diagonal brace.
4.2L V8 Engine (Driver Side)
1. Diagonal Brace
2. Bolts (3)
3. Screws (4)
1. Remove the three bolts (2) and
the diagonal brace (1).
2. Remove the four screws (3) on top of the engine air cleaner/
filter cover.
3. Lift the engine air cleaner/filter cover open on the hinge. 4. Lift and remove the engine air
cleaner/filter.
5. Inspect or replace the engine air cleaner/filter.
6. Reverse Steps 1–4 to reinstall the engine air cleaner/filter cover
and diagonal brace.4.2L V8 Engine (Passenger Side)
1. Screws (4)
2. Bolts (3)
3. Diagonal Brace
1. Remove the three bolts (2) and
the diagonal brace (3). 2. Remove the four screws (1) on
top of the engine air cleaner/
filter cover.
3. Lift the engine air cleaner/filter cover open on the hinge.
4. Lift and remove the engine air cleaner/filter.
5. Inspect or replace the engine air cleaner/filter.
6. Reverse Steps 1–4 to reinstall the engine air cleaner/filter cover
and diagonal brace.
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if the
engine backfires.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
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VEHICLE CARE 307
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.
For vehicles with the 4.2L engine, the
engine cooling fan may turn on and
run immediately after the vehicle is
turned off. This is normal.
2.0L L4 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
2. Engine Cooling Fan (Out of View)
3.0L V6 Engine
1. Engine Coolant Surge Tankand Pressure Cap
2. Engine Cooling Fan (Out of View)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
308 VEHICLE CARE
3.6L V6 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
2. Engine Cooling Fan (Out of View)
4.2L V8 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
2. Engine Cooling Fan (Out of View)
{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. 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.
The coolant level should be at the
cold fill mark on the middle of the
tank. If it is not, the vehicle may have
a leak at the radiator hoses, heater
hoses, radiator, water pump,
or somewhere else in the cooling
system.
{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.
If there seems to be no leak, with the
engine on, check to see if the electric
cooling fan is running. If the engine is
overheating, the fan should be
running. If it is not, the vehicle needs
service. Turn off the engine.

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Engine Coolant
The engine cooling system in the
vehicle is filled with a DEX-COOL
engine coolant mixture. This coolant
needs to be checked and replaced at
appropriate intervals. SeeMaintenance
Schedule 0383.
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, see
Engine Overheating 0312.
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. If using this mixture, nothing
else needs to be added. 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.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 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.
3.0L V6 Engine Coolant Surge Tank