GMC 2.8L Duramax Diesel 2020 Manual page 76

Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine
coolant mixture. See Recommended
Fluids and Lubricants 0 93 and
Maintenance Schedule 0 90.
The following explains the cooling
system and how to add coolant
when it is low. If there is a problem
with engine overheating, see Engine
Overheating 0 77.
A 50/50 mixture of clean, drinkable
water and DEX-COOL coolant will:
Give freezing protection down to
37 °C ( 34 °F).
Give boiling protection up to
129 °C (265 °F).
Protect against rust and
corrosion.
Help keep the proper engine
temperature.
Let the warning lights and
gauges work as they should.
What to Use
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.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant which will not damage
aluminum parts. If using this
mixture, nothing else needs to be
added.
If coolant has to be added more
than four times a year, have your
dealer check the vehicle cooling
system.
Vehicle Care
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, or by 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 (2.8L 4-Cylinder
Engine Pickup Models)
See Engine Coolant in the owner s
manual.
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