2022 CADILLAC CT4 engine

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
338 VEHICLE CARE
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.
2.0L L4 Engine
1. Engine Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
2.7L L4 Engine
1. Engine Coolant Surge Tank and Pressure Cap
2. Engine Cooling Fan (Out of View)
3. Cooling System Air Bleeder Cap
3.6L V6 Engine
1. Engine Coolant Surge Tank and Pressure Cap
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
VEHICLE CARE 339
{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 cooling system in the vehicle is
filled with DEX-COOL engine coolant.
SeeMaintenance Schedule 0408 and
Recommended Fluids and Lubricants
0 417.
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 0342.
What to Use
{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.
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.
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.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running. It is also
normal to see bubbles entering the
surge tank through the small hose.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
340 VEHICLE CARE
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 is not at or above the indicated
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, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
{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.
{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
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.
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.
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 or above the
indicated mark, add a 50/50 mixture
of clean, drinkable water and
DEX-COOL coolant at the coolant

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
VEHICLE CARE 341
surge tank, but be sure the cooling
system, including the coolant surge
tank pressure cap, is cool before you
do it.
2.0L L4 Engine and 3.6L
V6 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low.To use this feature:1. With a cold system, add coolant to
the indicated line on the
surge tank.
2. Replace the pressure cap on the surge tank.
3. Activate the service feature: 3.1. Connect the vehicle to a battery charger.
3.2. Turn the ignition to Service Mode. See Ignition Positions
0 232.
3.3. Turn off the air conditioning.
3.4. Set the parking brake. 3.5. At the same time, press the
accelerator and the brake
pedal for two seconds, then
release.
3.6. At the end of the cycle, check the coolant level in the surge
tank and add coolant if it is
below the indicated line. Turn
the ignition off, allow the
Electronic Control Module
(ECM) to go to sleep, about
two minutes, and repeat
Steps 3.2 –3.6.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat steps 3.2 –3.6.
The fill and air removal process will
run for approximately 15 minutes.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
342 VEHICLE CARE
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.
2.7L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low.
To use this feature:1. With a cold system unscrew the cooling system air bleeder cap.
If coolant can be seen through the
bleeder move to Step 3.
2. Add coolant through the surge tank until it is visible through the air
bleeder.
3. Replace the cooling system air bleeder cap.
4. Add coolant to the indicated line on the surge tank. 5. Replace the pressure cap on the
surge tank.
6. Activate the service feature: 6.1. Connect the vehicle to a battery charger.
6.2. Turn the ignition to Service Mode. See Ignition Positions
0 232.
6.3. Turn off the air conditioning.
6.4. Set the parking brake.
6.5. At the same time, press the accelerator and the brake
pedal for two seconds, then
release.
6.6. At the end of the cycle, check the coolant level in the surge
tank and add coolant if it is
below the indicated line. Turn
the ignition off, carefully
remove the pressure cap, refill
to the indicated line, replace
the pressure cap, and repeat
steps 6.2 –6.6.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove the pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat steps 6.2
–6.6.
The fill and air removal process will
run for approximately 15 minutes.
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 indicator to warn
of the engine overheating.
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0432.
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
VEHICLE CARE 343
running. If it is 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.
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 overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle 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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
344 VEHICLE CARE
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. SeeEngine Compartment
Overview 0326 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 to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
(Continued)
Caution (Continued)
expansion if freezing occurs,
which could damage the tank if
it is completely full.
Brakes
Disc brake linings, except J57 V-Series
Blackwing with carbon ceramic brakes,
have built-in wear indicators that
make a high-pitched warning sound
when the brake linings are worn and
new linings are needed. The sound
can come and go or can be heard all
the time when the vehicle is moving,
except when applying the brake pedal
firmly. The V-Series Blackwing has
electronic pad wear sensors. See Brake
Pad Life System (If Equipped) 0346
{Warning
The brake wear warning sound
means that soon the brakes will not
work well. That could lead to a
crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake linings could result in costly
brake repairs.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake linings for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0424.
Brake linings should be replaced as
complete axle sets.
Brake Squeal and Brake Dust
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied, clearing up
following several applies. This does
not mean something is wrong with
the brakes.
Vehicles equipped with high
performance brake systems provide
superior fade resistance, but will
produce increased brake squeal and

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-15283641) -
2022 - CRC - 10/12/21
346 VEHICLE CARE
V-Series Blackwing Brake
Burnish Procedure for Corrosion
Cleanup
Corrosion spotting and grooving on
the brake rotor surface may appear
after the vehicle sits for an extended
period of time, especially in high
humidity. This corrosion may result in
brake pulsation and noise. To help
restore optimal braking performance
and reduce noise, complete the
following procedure:
Caution
Performing the brake burnish
procedure on a base brake system
can result in brake damage.
Perform this procedure only on dry
pavement, in a safe manner, and in
compliance with all local and state
ordinances/laws regarding motor
vehicle operation.
Caution
The new vehicle break-in period
should be completed before
performing the brake burnishing (Continued)
Caution (Continued)
procedure or damage may occur to
the powertrain/engine. See New
Vehicle Break-In 0231.
Caution
Brake fade can occur during this
burnish procedure and can cause
brake pedal travel and force to
increase. This could extend
stopping distance until the brakes
are fully burnished.
Completing the following procedure as
instructed will not damage the brakes.
The brake pads may smoke and
produce an odor. The braking force
and pedal travel may increase. After
the procedure, the brake pads may
appear white at the rotor contact. 1. Using the G-Force Gauge in the HUD display, apply the brakes 10
times starting at 100 km/h
(60 mph) to 50 km/h (30 mph)
while decelerating at 0.4g.
SeeHead-Up Display (HUD) 0115. This is a medium brake application.
Drive for at least 0.5 km (0.3 mi)
between applying the brakes.
2. If further cleanup of the brake discs is needed, repeat this
procedure with 0.7g applications.
As with all high performance brake
systems, some amount of brake squeal
is normal.
Brake Pad Life System (If
Equipped)
When to Change Brake Pads
If equipped, this system estimates the
remaining life of the front and rear
brake pads. Brake Pad Life is displayed
in the Driver Information Center
(DIC), along with a percentage for
each axle. The system must be reset
every time the brake pads are
changed.
When the system has determined that
the brake pads need to be replaced, a
message displays, which may include
mileage remaining.
Brake pads should always be replaced
as complete axle sets.