GMC 2018 Terrain Owner's Manual page 233

232 Vehicle Care
Warning (Continued)
there would not be an 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. 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
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard
GMW3420 and clean, drinkable
water. Anything else can cause
damage to the engine cooling
system and the vehicle, which
would not be covered by the
vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or pouring 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.
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 mark is not
visible, add a 50/50 mixture of
clean, drinkable water and
DEX-COOL coolant at the coolant
surge tank to the top rib on the
middle of the tank, but be sure the
cooling system is cool before this is
done. See Engine Overheating
0 234.