2023 CADILLAC XT6 engine

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
Vehicle Care 377
3.6L V6 Engine
1. Electric Engine CoolingFan (Out of View)
2. 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 cooling system in
the vehicle are filled with
DEX-COOL engine coolant
mixture. This coolant needs to
be checked and changed at
appropriate levels. See
Recommended Fluids and
Lubricants 0458 and
Maintenance Schedule 0454.
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 0381.
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
378 Vehicle Care
.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 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.
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 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. See
Engine Overheating
0381.
The coolant surge tank is
located in the engine
compartment on the driver
side of the vehicle. See Engine
Compartment Overview 0367.
How to Add Coolant to the
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
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
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
Vehicle Care 379
Warning (Continued)
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.
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.
Coolant Fill Instructions
(3.6L Engine Only)
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 tankwith 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

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
380 Vehicle Care
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
Step 1–6.
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.
Automatic Coolant
Service Fill Instructions
(2.0L Engine Only)
If equipped, this feature
assists in filling and removing
air from the cooling system
after service of components
or when coolant is added after
being too low. To activate the fill and air
removal process:
1. With a cold system,
disconnect the vent line
from the port near the cap
on the surge tank. Add
coolant to the indicated
mark on the surge tank.
2. Reconnect the vent line to the surge tank and replace
the cap on the surge tank.
3. Connect the vehicle to a battery charger.
4. Put the vehicle in Service Mode. See Ignition
Positions 0257. 5. Turn off the air
conditioning.
6. Set the parking brake.
7. At the same time, press the accelerator and the
brake for automatic
transmission vehicles for
two seconds, then release.
At the end of the cycle, check
the coolant level in the surge
tank and add coolant, if it is
low. Turn off the vehicle, allow
the Engine Control Module
(ECM) to go to sleep, about
two minutes, and repeat
steps 3-7.
Listen for pump activation and
movement of the control
valves while watching the level
of the tank. If the tank
empties, turn the ignition off,
carefully remove the surge
tank cap, refill to the indicated
mark and repeat steps 3-6.
The fill and air removal
process will run for
approximately 10 minutes.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
Vehicle Care 381
Engine Overheating
The vehicle has several
indicators to warn of the
engine overheating.
There is an engine coolant
temperature gauge on the
instrument cluster. See Engine
Coolant Temperature Gauge
0131. The vehicle may also
display a message on the
Driver Information
Center (DIC).
If the decision is made not to
lift the hood when this
warning appears, get service
help right away. See Roadside
Assistance Program 0470.
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.
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
382 Vehicle Care
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
The appropriate message will
appear in the Driver
Information Center (DIC) when
the fluid level is low.
Open the cap with the washer
symbol on it. Add washer fluid until the tank is full. See
Engine Compartment
Overview
0367 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.
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
384 Vehicle Care
Brake Fluid
The brake master cylinder
reservoir is filled with GM
approved DOT 4 brake fluid as
indicated on the reservoir cap.
See Engine Compartment
Overview0367 for the
location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on
a level surface, the brake fluid
level should be between the
minimum and maximum marks
on the brake fluid reservoir.
There are only two reasons
why the brake fluid level in the
reservoir may go down:
.Normal brake lining wear.
When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will
not work well.
Always clean the brake fluid
reservoir cap and the area
around the cap before
removing it.
Do not top off the brake fluid.
Adding fluid does not correct a
leak. If fluid is added when the
linings are worn, there will be
too much fluid when new
brake linings are installed. Add
or remove fluid, as necessary,
only when work is done on the
brake hydraulic system.
{Warning
If too much brake fluid is
added, it can spill on the
engine and burn, if the
engine is hot enough. You or
others could be burned, and
the vehicle could be (Continued)
Warning (Continued)
damaged. Add brake fluid
only when work is done on
the brake hydraulic system.
When the brake fluid falls to a
low level, the brake warning
light comes on. See Brake
System Warning Light 0136.
Brake fluid absorbs water over
time which degrades the
effectiveness of the brake
fluid. Replace brake fluid at the
specified intervals to prevent
increased stopping distance.
See Maintenance Schedule
0 454.
What to Add
Use only GM approved DOT 4
brake fluid from a clean, sealed
container. See Recommended
Fluids and Lubricants 0458.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-16405819) -
2023 - CRC - 3/22/22
Vehicle Care 385
{Warning
The wrong or contaminated
brake fluid could result in
damage to the brake
system. This could result in
the loss of braking leading to
a possible injury. Always use
the proper GM approved
brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Immediately wash
off any painted surface.
Battery - North
America
The original equipment battery
is maintenance free. Do not
remove the cap and do not
add fluid.Refer to the replacement
number on the original battery
label when a new battery is
needed. For replacement of
the battery, see your dealer.
The vehicle has an Absorbent
Glass Mat (AGM) 12-volt
battery. Installation of a
standard 12-volt battery will
result in reduced 12-volt
battery life.
When using a 12-volt battery
charger on the 12-volt AGM
battery, some chargers have
an AGM battery setting on the
charger. If available, use the
AGM setting on the charger,
to limit charge voltage to
14.8 volts.
{Warning
WARNING:
Battery posts,
terminals and related
accessories can expose you
to chemicals including lead
and lead compounds, which
are known to the State of
(Continued)
Warning (Continued)
California to cause cancer
and birth defects or other
reproductive harm. Wash
hands after handling. For
more information go to
www.P65Warnings.ca.gov.
See California Proposition
65 Warning 01.
Stop/Start System
This vehicle has a Stop/Start
system to shut off the engine
to help conserve fuel. See
Stop/Start System 0259.
Vehicle Storage
{Warning
Batteries have acid that can
burn you and gas that can
explode. You can be badly
hurt if you are not careful.
Always wear eye protection.
(Continued)