cooling CADILLAC CT6 2017 1.G User Guide

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 255
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. Pull out 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. 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
you are driving.
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
3.0L V6 Twin Turbo Engine
1. Engine Coolant Surge Tank
and Pressure Cap 2. Engine Cooling Fan (Out
of View)
3.6L V6 Engine
1. Engine Coolant Surge Tankand Pressure Cap
2. Engine Cooling Fan (Out of View)
{Warning
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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{Warning
Heater and radiator hoses, and
other engine parts, can be very hot.
Do not touch them. If you do, you
can be burned.
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 fire, and you could be
burned. Get any leak fixed before
you drive the vehicle.
Caution
Using coolant other than
DEX-COOL®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner. 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
filled with DEX-COOL®engine coolant.
This coolant needs to be checked and
replaced at appropriate intervals. See
Maintenance Schedule 0311.
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 0259.
What to Use
{Warning
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water and
other liquids, can boil before the
proper coolant mixture will. The
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
(Continued)
Warning (Continued)
fire 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
−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 CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 257
Caution
If improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
mixture can freeze and crack engine
cooling parts. The repairs would not
be covered by the vehicle warranty.
Use only the proper mixture of
engine coolant for the cooling
system. SeeRecommended Fluids
and Lubricants 0318.
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
3.6L V6 Engine Coolant Surge Tank
Check to see if coolant is visible in the
coolant surge tank. If the coolant
inside the coolant surge tank is boiling, do not do anything else until
it cools down. If coolant is visible but
the coolant level mark is not visible,
add a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant at the coolant surge tank to
the top rib on the middle of the tank,
but be sure the cooling system is cool
before this is done. See
Engine
Overheating 0259.
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0247.
How to Add Coolant to the
Coolant Surge Tank
Caution
This vehicle has a specific coolant
fill procedure. Failure to follow this
procedure could cause the engine to
overheat and be severely damaged.
If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but the
coolant level is not at the indicated
level mark, add a 50/50 mixture of

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
258 VEHICLE CARE
clean, drinkable water and DEX-COOL
coolant at the coolant surge tank, but
be sure the cooling system, including
the coolant surge tank pressure cap, is
cool before you do it.
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn the
cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure cap
to cool.
{Warning
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water and
other liquids, can boil before the
proper coolant mixture will. The
coolant warning system is set for
the proper coolant mixture. With(Continued)
Warning (Continued)
plain water or the wrong mixture,
the engine could get too hot but
you would not get the 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.
Caution
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.
{Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol(Continued)
Warning (Continued)
and it will burn if the engine parts
are hot enough. Do not spill coolant
on a hot engine.
1. Remove the coolant surge tank pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is 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 out the
discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with the proper mixture to the
indicated level mark.
4. With the coolant surge tank pressure cap off, start the engine
and let it run until you can feel

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 259
the upper radiator hose getting
hot. Watch out for the engine
cooling fan.
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
indicated level mark.
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 1–6.
If the coolant still is not at the
proper level when the system
cools down again, see your
dealer.
Caution
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.
Engine Overheating
The vehicle has several indicators to
warn of the engine overheating.
There is an engine coolant
temperature gauge and an engine
coolant temperature warning light on
the instrument cluster. See Engine
Coolant Temperature Gauge 0124 and
Engine Coolant Temperature Warning
Light 0132. The vehicle may also
display a message on the Driver
Information Center (DIC). See Engine
Cooling System Messages 0143.
If the decision is made not to lift the
hood when this warning appears, get
service help right away.
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 fan is running.
If the engine is overheating, the fan
should be running. If it is not, do not
continue to run the engine. Have the
vehicle serviced.Caution
Running the engine without coolant
may cause damage or a fire. Vehicle
damage would not be covered by
the vehicle warranty.
If Steam Is Coming from the
Engine Compartment
{Warning
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. Just 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 engine
is overheated, the liquids in it can
catch fire. You or others could be
badly burned. Stop the engine if it
overheats, and get out of the
vehicle until the engine is cool.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
260 VEHICLE CARE
If No Steam Is Coming from the
Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen or
heard, the problem may not be too
serious. Sometimes the engine can get
a little too hot when the vehicle:
.Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
If the overheat warning is displayed
with no sign of steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the
engine idle.
If the engine coolant temperature
gauge is no longer in the overheated
area or the engine coolant
temperature warning light no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly for about 10 minutes. Keep a safe
distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.
Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See
Engine Compartment
Overview 0247 for reservoir location.
Caution
.
Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
. Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
. Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 289
air, replace it. Some aluminum wheels
can be repaired. See your dealer if any
of these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the same
load-carrying capacity, diameter,
width, offset, and be mounted the
same way as the one it replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor System
(TPMS) sensors with new GM original
equipment parts.
{Warning
Using the wrong replacement
wheels, wheel bolts, or wheel nuts
can be dangerous. It could affect
the braking and handling of the
vehicle. Tires can lose air, and
cause loss of control, causing a
crash. Always use the correct wheel,
wheel bolts, and wheel nuts for
replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or odometer
calibration, headlamp aim, bumper
height, vehicle ground clearance,
and tire or tire chain clearance to
the body and chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used one
is dangerous. How it has been used
or how far it has been driven may
be unknown. It could fail suddenly
and cause a crash. When replacing
wheels, use a new GM original
equipment wheel.
Tire Chains
Caution
Use tire chains only where legal and
only when necessary. Use low
profile chains that add no more
than 10 mm thickness to the tire
tread and inner sidewall. Use chains
that are the proper size for the tires.
Install them on the tires of the rear
axle. Do not use chains on the tires
of the front axle. Tighten them as
tightly as possible with the ends
securely fastened. Drive slowly and
follow the chain manufacturer's
instructions. If the chains contact
the vehicle, stop and retighten
them. If the contact continues, slow
down until it stops. Driving too fast
or spinning the wheels with chains
on will damage the vehicle.
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. SeeTires0276.
If air goes out of a tire, it is much

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
SERVICE AND MAINTENANCE 313
Maintenance Schedule
Additional Required Services -
Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. (1)@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace engine air cleaner filter. (4)@ @ @ @ @ @ @ @ @ @
Replace spark plugs. Inspect spark plug wires. (3.0L
Twin Turbo Engine)@ @
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine)@
Drain and fill engine cooling system. (5)@
Change transfer case fluid. (6)@
Change front and rear axle fluid.@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
314 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation0284.
(2) Or every two years, whichever
comes first. More frequent passenger
compartment air filter replacement
may be needed if driving in areas with
heavy traffic, poor air quality, high
dust levels, or environmental
allergens. Passenger compartment air
filter replacement may also be needed
if there is reduced airf low, window
fogging, or odors. Your GM dealer can
help determine when to replace the
filter. (3)
Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(4) Or every two years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
(5) Or every five years, whichever
comes first. See Cooling System0255.
(6) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate
the transfer case fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and should
be replaced. (7)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(8) Replace brake fluid every five
years. See Brake Fluid 0262.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
SERVICE AND MAINTENANCE 315
Maintenance Schedule
Additional Required Services -
Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. (1)@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace engine air cleaner filter. (4)@ @ @ @ @ @ @ @ @ @
Replace spark plugs. Inspect spark plug wires. (3.0L
Twin Turbo Engine)@ @
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine)@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid. (5)@@@
Change front and rear axle fluid.@@@
Drain and fill engine cooling system. (6)@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)