2021 CADILLAC CT5 cooling

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
322 VEHICLE CARE
{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.
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)
3.0L 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 CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 323
{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.
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.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant.
SeeMaintenance Schedule 0383 and
Recommended Fluids and Lubricants
0 392. 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
0326.
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 CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
324 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(Continued)
Warning (Continued)
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
surge tank, but be sure the cooling
system, including the coolant surge
tank pressure cap, is cool before you
do it.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 325
2.0L 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 too low.
To use the service feature:
1. With a cold system, add coolant tothe indicated line on the
surge tank.
2. Replace the pressure cap on the surge tank. To activate the service feature:
1. Connect the vehicle to a battery charger.
2. Turn the ignition on. See Ignition
Positions 0224.
3. Turn off the air conditioning.
4. Set the parking brake.
5. At the same time, press the accelerator and the brake pedal for
two seconds, then release.
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 2–6.
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 2–6.
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.
3.0L V6 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. 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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
326 VEHICLE CARE
3. Fill the surge tank with the propermixture 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 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
surge tank until the level reaches
the indicated level mark.
5. Replace the pressure cap tightly. 6. Check the level in the surge tank
after the engine is shut off and the
cooling system has cooled down.
If the coolant is not at the proper
level, repeat 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 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 0405.
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
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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 327
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
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See
Engine Compartment
Overview 0313 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)

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 361
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
{Warning
Do not use tire chains. There is not
enough clearance. Tire chains used
on a vehicle without the proper(Continued)
Warning (Continued)
amount of clearance can cause
damage to the brakes, suspension,
or other vehicle parts. The area
damaged by the tire chains could
cause loss of control and a crash.
Use another type of traction device
only if its manufacturer
recommends it for the vehicle's tire
size combination and road
conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive slowly
and readjust or remove the traction
device if it contacts the vehicle. Do
not spin the wheels. If traction
devices are used, install them on
the rear tires.
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. If air goes out of
a tire, it is much more likely to leak
out slowly. SeeTires0342 for additional information. But if there
ever is a blowout, here are a few tips
about what to expect and what to do:
If a front tire fails, the flat tire creates
a drag that pulls the vehicle toward
that side. Take your foot off the
accelerator pedal and grip the steering
wheel firmly. Steer to maintain lane
position, and then gently brake to a
stop, well off the road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and may
require the same correction as used in
a skid. Stop pressing the accelerator
pedal and steer to straighten the
vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off
the road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been
driven on while severely
underinflated or flat may cause a
blowout and a serious crash. Never
attempt to re-inflate a tire that has
(Continued)

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 383
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. SeeEngine
Oil 0316.
Once a Month
.Check the tire inflation pressures.
See Tire Pressure 0349.
.Inspect the tires for wear. See Tire
Inspection 0355.
.Check the windshield washer fluid
level. See Washer Fluid 0327.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km (600 mi). If driven
under the best conditions, the engine
oil life system may not indicate the
need for vehicle service for up to a
year. The engine oil and filter must be
changed at least once a year and the
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System
0318.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0355.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0316 and
Engine Oil Life System 0318.
.If equipped, check the air filter
life percentage. If necessary, replace
the engine air filter and reset the
engine air filter life system. See
Engine Air Filter Life System 0319.
If the vehicle is not equipped with
the engine air filter life system,
inspect the engine air cleaner filter.
See Engine Air Cleaner/Filter 0320.
.Check engine coolant level. See
Cooling System 0322.
.Check windshield washer fluid level.
See Washer Fluid 0327.
.Check tire inflation pressures. See
Tire Pressure 0349.
.Inspect tire wear. See Tire Inspection
0 355.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0372.
.Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0372.