Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
250 VEHICLE CARE
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
3.6L V6 Engine
1. Electric Engine Cooling Fans(Out of View)
2. Coolant Surge Tank and Pressure Cap
3.6L V6 Twin Turbo Engine
1. Electric Engine Cooling Fans(Out of View)
2. Charged Air Coolant (CAC) Bottle and Pressure Cap
3. 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 and Charged Air Coolant
(CAC) cooling systems in the vehicle
are filled with DEX-COOL engine
coolant mixture.
See Recommended Fluids and
Lubricants 0332 and Maintenance
Schedule 0322.
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 0253.
Cadillac XTS Owner Manual (GMNA-Localizing-U.S./Canada-12032610) -
2019 - crc - 8/22/18
252 VEHICLE CARE
How to Add Coolant to the
Surge Tank
{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
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
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.
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 tank with
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 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
Steps 1–5.
