Page 286 of 417

GMC Canyon/Canyon Denali Owner Manual (GMNA-Localizing-U.S./Canada-
11354423) - 2018 - crc - 10/12/17
Vehicle Care 285
2.5L L4 Gas Engine Shown, 2.8LL4 Diesel Engine Similar
1. Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
3.6L V6 Engine
1. Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
{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 cooling system in the vehicle is
filled with DEX-COOL engine
coolant mixture.
See Recommended Fluids and
Lubricants 0370 andMaintenance
Schedule 0361.
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 0288.
Page 288 of 417

GMC Canyon/Canyon Denali Owner Manual (GMNA-Localizing-U.S./Canada-
11354423) - 2018 - crc - 10/12/17
Vehicle Care 287
Be sure the cooling system is cool
before this is done.
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant 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
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.
{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.
Warning
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 cap and remove it.
Page 289 of 417

GMC Canyon/Canyon Denali Owner Manual (GMNA-Localizing-U.S./Canada-
11354423) - 2018 - crc - 10/12/17
288 Vehicle Care
3. Fill the coolant surge tank withthe proper mixture to the mark
pointed to on the front of the
coolant surge tank.
4. With the coolant surge tank cap off, start the engine and let
it run until the upper radiator
hose starts 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
mixture to the coolant surge
tank until the level reaches the
mark pointed to on the front of
the coolant surge tank.
5. Replace the cap tightly.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–6.Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating
The vehicle has an engine coolant
temperature gauge on the
instrument cluster to warn of engine
overheating. See Engine Coolant
Temperature Gauge 0117.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away. If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0
382.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Then check to see if the engine
cooling fan is running. If the engine
is overheating, the fan should be
running. If it is not, do not continue
to run the engine and have the
vehicle serviced.
If Steam Is Coming from the
Engine Compartment
{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, (Continued)