Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
252 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.
1. Electric Engine Cooling Fan(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 is filled with DEX-COOL engine
coolant mixture. This coolant needs to
be checked and changed at
appropriate levels. See Recommended
Fluids and Lubricants 0329 and
Maintenance Schedule 0319.
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 0255.
Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
254 VEHICLE CARE
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
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. If topping off the level in thecoolant surge tank, add the
proper mixture until the level
reaches the mark on the front of
the tank and replace the cap.
Operate the vehicle. Repeat steps
1–3, as necessary.
If filling the system (such as
after servicing), follow the
Automatic Coolant Service Fill
Instructions.
