cooling CADILLAC XT6 2021 User Guide

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
318 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 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. SeeEngine Overheating 0320.
The coolant surge tank is in the
engine compartment on the driver
side of the vehicle. See Engine
Compartment Overview 0308.
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 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
(Continued)
Caution (Continued)
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 319
3. Fill the coolant surge tank with theproper 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
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
320 VEHICLE CARE
4. Put the vehicle in Service Mode.See Ignition Positions 0232.
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.
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 0113. 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
Service 0401.
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 321
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
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 0308 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
expansion if freezing occurs,
which could damage the tank if
it is completely full.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
356 VEHICLE CARE
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels were aligned and
balanced at the factory to provide the
longest tire life and best overall
performance. Adjustments to wheel
alignment and tire balancing are not
necessary on a regular basis. Consider
an alignment check if there is unusual
tire wear or the vehicle is significantly
pulling to one side or the other. Some
slight pull to the left or right,
depending on the crown of the road
and/or other road surface variations
such as troughs or ruts, is normal.
If the vehicle is vibrating when driving
on a smooth road, the tires and
wheels may need to be rebalanced.
See your dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,
cracked, or badly rusted or corroded.
If wheel nuts keep coming loose, the
wheel, wheel bolts, and wheel nutsshould be replaced. If the wheel leaks
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, resulting in 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
{Warning
If the vehicle has 265/45R21 size
tires, do not use tire chains. There
is not enough clearance. Tire chains
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
SERVICE AND MAINTENANCE 381
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 System0313.
Engine Air Filter Change
When the REPLACE AT NEXT OIL
CHANGE message displays, the engine
air filter should be replaced at the
next engine oil change. When the
REPLACE ENGINE AIR FILTER SOON
message displays, the engine air filter
should be replaced at the earliest
convenience. Reset the engine air
filter life system after the engine air
filter is replaced. See Engine Air Filter
Life System 0314.
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 Rotation0351.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0311 and
Engine Oil Life System 0313.
.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 0314.
.Check engine coolant level. See
Cooling System 0316.
.Check windshield washer fluid level.
See Washer Fluid 0321.
.Check tire inflation pressures. See
Tire Pressure 0343.
.Inspect tire wear. See Tire Inspection
0 350.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0370.
.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 0370.
.Inspect power steering for proper
electrical connections, binding,
cracks, chafing, etc.
.Visually inspect halfshafts and drive
shafts for excessive wear, lubricant
leaks, and/or damage including:
tube dents or cracks, constant
velocity joint or universal joint
looseness, cracked or missing boots,
loose or missing boot clamps, center
bearing excessive looseness, loose or
missing fasteners, and axle seal
leaks.
.Check restraint system components.
See Safety System Check 060.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
SERVICE AND MAINTENANCE 383
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 and perform Required Services. Check
engine oil level and oil life percentage. Change
engine oil and filter, if needed.
Check engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
Inspect evaporative control system. (2)@ @@
Replace spark plugs. Inspect spark plug wires and/or
boots. 2.0L Engine.@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. 3.6L Engine.@
Change rear axle fluid, if equipped with AWD. (3)@
Drain and fill engine cooling system. (4)@
Visually inspect accessory drive belts. (5)@
Replace brake fluid. (6)
Replace front and rear wiper blades. (7)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (8)@ @
Replace air conditioning desiccant. (9)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
384 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Normal
(1) 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.
(2) Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(3) 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.
(4) Or every five years, whichever
comes first. See Cooling System0316. (5)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(6) Replace brake fluid every five
years. See Brake Fluid 0322.
(7) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0325.
(8) Or every 10 years, whichever
comes first. See Gas Strut(s)0326.
(9) Replace air conditioning desiccant
every seven years.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
SERVICE AND MAINTENANCE 385
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 and perform Required Services. Check
engine oil level and oil life percentage. Change
engine oil and filter, if needed.
Check engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
Inspect evaporative control system. (2)@ @@
Change automatic transmission fluid.@@@
Replace spark plugs. Inspect spark plug wires and/or
boots. 2.0L Engine.@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. 3.6L Engine.@
Change rear axle fluid, if equipped with AWD. (3)@ @
Drain and fill engine cooling system. (4)@
Visually inspect accessory drive belts. (5)@
Replace brake fluid. (6)
Replace front and rear wiper blades. (7)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (8)@@
Replace air conditioning desiccant. (9)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
386 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Severe
(1) 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.
(2) Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(3) 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.
(4) Or every five years, whichever
comes first. See Cooling System0316. (5)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(6) Replace brake fluid every five
years. See Brake Fluid 0322.
(7) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0325.
(8) Or every 10 years, whichever
comes first. See Gas Strut(s)0326.
(9) Replace air conditioning desiccant
every seven years.
Special Application
Services
.Severe Commercial Use Vehicles
Only: Lubricate chassis components
every oil change.
.Have underbody flushing service
performed. See "Underbody
Maintenance" in Exterior Care0370.
Additional Maintenance
and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer
perform these services —their trained
dealer technicians know your vehicle
best. Your dealer can also perform a
thorough assessment with a
multi-point inspection to recommend
when your vehicle may need
attention.
The following list is intended to
explain the services and conditions to
look for that may indicate services are
required.
Battery
The 12-volt battery supplies power to
start the engine and operate any
additional electrical accessories.
.To avoid break-down or failure to
start the vehicle, maintain a battery
with full cranking power.