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
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
