Page 337 of 496

Black plate (19,1)Cadillac CTS/CTS-V Owner Manual - 2011
Vehicle Care 10-19
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
When you decide it is safe to lift the
hood, here is what you will see:
A. Electric Engine Cooling Fan(s)(Out of View)
B. Coolant Surge Tank and Pressure Cap
{WARNING
An electric engine cooling fan
under the hood 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
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
Notice: Using coolant other than
DEX-COOL
®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine coolant could require changing
sooner, at 50 000 km
(30,000 miles) or 24 months,
whichever occurs first. Any
repairs would not be covered by
the vehicle warranty. Always use
DEX-COOL
®(silicate-free) coolant
in the vehicle.
Engine Coolant
The cooling system in the vehicle
for all engines and the intercooler is
filled with DEX-COOL
®. This coolant
is designed to remain in the vehicle
for five years or 240 000 km
(150,000 miles), whichever occurs
first.
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
on
page 10‑24.
Page 338 of 496

Black plate (20,1)Cadillac CTS/CTS-V Owner Manual - 2011
10-20 Vehicle Care
What to Use
{WARNING
Adding only plain water to the
cooling system can be
dangerous. Plain water, or some
other liquid such as alcohol, can
boil before the proper coolant
mixture will. The vehicle's coolant
warning system is set for the
proper coolant mixture. With plain
water or the wrong mixture, the
engine could get too hot but you
would not get the overheat
warning. The engine could catch
fire and you or others could be
burned. Use a 50/50 mixture of
clean, drinkable water and
DEX-COOL
®coolant.Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®
coolant. If using this mixture,
nothing else needs to be added.
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.
.Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
The engine coolant reservoir is
located in the engine compartment
on the driver side of the vehicle.
See Engine Compartment Overview
on page 10‑6.
Check to see if coolant is visible in
the surge tank. If the coolant inside
the surge tank is boiling, do not do
anything else until it cools down.
If coolant is visible but the coolant
level is not at or above the FULL
COLD mark, add a 50/50 mixture of
clean, drinkable water and
DEX-COOL
®coolant at the coolant
surge tank, but be sure the cooling
system is cool before this is done.
If the engine is warm or hot, the
coolant level should be at or above
the FROID/FULL COLD line on the
side of the coolant surge tank. If the
engine is cold, the coolant level
should be near the FROID/FULL
Page 339 of 496

Black plate (21,1)Cadillac CTS/CTS-V Owner Manual - 2011
Vehicle Care 10-21
COLD line on the side of the coolant
surge tank. If it is not, there could
be a leak in the cooling system.
How to Add Coolant to the
Surge Tank
{WARNING
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Notice: This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
{WARNING
An electric engine cooling fan
under the hood 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
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you turn
the surge tank pressure
cap —even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the surge tank
pressure cap, is hot. Wait for the
cooling system and surge tank
pressure cap to cool if you ever
have to turn the pressure cap. If coolant is needed, add the proper
DEX-COOL
®coolant mixture at the
coolant surge tank.
If no coolant is visible in the surge
tank, add coolant as follows:
1. Remove the coolant surge tank pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no longer
hot. Turn the pressure cap
slowly counterclockwise about
one-quarter turn and then stop.
If you hear a hiss, wait for that to
stop. A hiss means there is still
some pressure left.
Page 340 of 496

Black plate (22,1)Cadillac CTS/CTS-V Owner Manual - 2011
10-22 Vehicle Care
2. Then keep turning the pressurecap slowly and remove it.3. Fill the coolant surge tank withthe proper mixture, to slightly
above the FROID/FULL COLD
line on the side 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. The upper radiator
hose is the top hose coming out
of the radiator, on the passenger
side of the vehicle. 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
FROID/FULL COLD line on the
side of the coolant surge tank.
5. Then replace the pressure cap. Be sure the pressure cap is
hand-tight and fully seated.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Recheck the coolant level in the
bottle next time you use your
vehicle to ensure the system is full
when cold.