Page 224 of 352

Black plate (16,1)Chevrolet Sonic Owner Manual - 2012
10-16 Vehicle Care
1.8L L4 Engine
A. Engine Electric Cooling Fan (Out of View)
B. Engine 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 may require changing
sooner, at the first maintenance
service after each 30,000 miles
(50 000 km) 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 is
filled with DEX-COOL engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), 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 10‑20.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
(Continued)
Page 225 of 352

Black plate (17,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-17
WARNING (Continued)
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. 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.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.
Checking Coolant
The vehicle must be on a level
surface when checking the coolant
level.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running.
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 is not at or above the mark
pointed to, add a 50/50 mixture of
clean drinkable water and
DEX-COOL coolant.
Be sure the cooling system is cool
before this is done.
Page 226 of 352

Black plate (18,1)Chevrolet Sonic Owner Manual - 2012
10-18 Vehicle Care
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
Notice:This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible
but the coolant level is not at
the indicated level 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, including the
coolant surge tank pressure cap,
is cool before you do it.
{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 coolant surge tank pressure
cap —even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the coolant
surge tank pressure cap, is hot.
Wait for the cooling system and
coolant surge tank pressure cap
to cool if you ever have to turn
the pressure cap.
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The 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.
Notice: In cold weather, water
can freeze and crack the engine,
radiator, heater core and other
parts. Use the recommended
coolant and the proper coolant
mixture.
Page 227 of 352

Black plate (19,1)Chevrolet Sonic Owner Manual - 2012
Vehicle Care 10-19
{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.
1.4L Engine Shown, 1.8L EngineSimilar
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 of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with
the proper DEX-COOL coolant
mixture to the indicated
level mark. 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 fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
DEX-COOL coolant mixture to
the coolant surge tank until the
level reaches the indicated
level mark.
5. Replace the pressure cap. Be sure the pressure cap is
hand-tight.
Check the level in the coolant surge
tank when the cooling system has
cooled down. If the coolant is not at
the proper level, repeat Steps 1
through 3 and reinstall the pressure
cap. If the coolant still is not at the
proper level when the system cools
down again, see your dealer.