
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 361
.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, 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
The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
0 345.
The vehicle must be on a level
surface when checking the coolant
level.
5.3L V8 Shown, 4.3L V6, 6.0L V8, and 6.2L V8 Similar
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, wait until it cools down. The
coolant level should be at or above the full cold mark. If it is not, there
may be a leak in the cooling
system.
If coolant is visible but the coolant
level is not at or above the full cold
mark, see
“How to Add Coolant to
the Coolant Surge Tank for Gasoline
Engines,” following.
How to Add Coolant to the
Coolant Surge Tank for
Gasoline Engines
If the vehicle has a diesel engine,
see“Cooling System” in the
Duramax diesel supplement for the
proper coolant fill procedure.
{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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
362 Vehicle Care
{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.
If no coolant is visible in the surge
tank, add coolant.
Light-Duty
Coolant Surge
Tank
Pressure CapHeavy-Duty
Coolant Surge
Tank
Pressure Cap
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 full
turn. If a hiss is heard, wait for
that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly, and remove it.
3. Fill the coolant surge tank with the proper mixture to the full
cold mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90 °C (195 °F).
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
full cold mark.
5. Replace the pressure cap tightly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 363
6. Verify coolant level after theengine 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
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
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. The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See
Engine Coolant
Temperature Gauge 0144.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 469.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be running. If they are 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,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 365
Caution (Continued)
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil 0350.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan will slow down when additional
cooling is not required and the
clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fan(s), the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Power Steering Fluid
(1500 Series)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
See
Engine Compartment Overview
0 345 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 367
Caution
.Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
. Do not use engine coolant
(antifreeze) in the
windshield washer. It can
damage the windshield
washer system and paint.
. Do not mix water with
ready-to-use washer fluid.
Water can cause the
solution to freeze and
damage the washer fluid
tank and other parts of the
washer system.
. When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
. Fill the washer fluid tank
only three-quarters full when
it is very cold. This allows
(Continued)
Caution (Continued)
for fluid expansion if
freezing occurs, which could
damage the tank if it is
completely full.
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in Capacities and
Specifications 0461.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
448 Service and Maintenance
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil 0350.
Once a Month
. Check the tire inflation
pressures. See Tire Pressure
0 397.
. Inspect the tires for wear. See
Tire Inspection 0404.
. Check the windshield washer
fluid level. See Washer Fluid
0 366.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system may not
indicate the need for vehicle service
for up to a year. The engine oil and filter must be changed at least once
a year and the oil life system must
be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
See
Engine Oil Life System 0353.
Passenger Compartment Air
Filter
The passenger compartment air
filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
Inspect the passenger compartment
air filter every 36 000 km/
22,500 miles or two years,
whichever comes first. Replace if
necessary. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels. Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi
Rotate the tires, if recommended for
the vehicle, and perform the
following services. See
Tire
Rotation 0405.
. Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil 0350 andEngine Oil Life
System 0353.
. Check engine coolant level. See
Cooling System 0359.
. Check windshield washer fluid
level. See Washer Fluid 0366.
. Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care 0435. Replace worn or
damaged wiper blades. See
Wiper Blade Replacement
0 375.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
456 Service and Maintenance
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
This maintenance section applies to vehicles with a gasoline engine. If the vehicle has a diesel engine and/or an
Allison Transmission, see“Recommended Fluids and Lubricants” in the Duramax diesel supplement.
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.
Usage Fluid/Lubricant
Automatic Transmission (6-Speed Transmission) DEXRON-VI Automatic Transmission Fluid.
Automatic Transmission (8-Speed Transmission) DEXRON-HP Automatic Transmission Fluid (GM Part No. 19331925, in
Canada 19300537).
Chassis Lubrication Chassis Lubricant (GM Part No. 12377985, in Canada 88901242) or lubricant meeting requirements of NLGI #2, Category LB or GC-LB.
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL coolant. SeeCooling System 0359.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 is recommended. See Engine Oil0350.
Floor Shift Linkage Lubriplate Lubricant Aerosol (GM Part No. 89021668, in Canada 89021674) or lubricant meeting requirements of NLGI #2 Category LB or GC-LB.
Front Axle Driveshaft Splines (All
1500/2500/3500 Series) and Rear Axle Driveshaft Splines (All 1500 Series) Spline Lubricant, Special Lubricant (GM Part No. 19257121, in
Canada 19257122).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 493
California (cont'd)Perchlorate Materials
Requirements . . . . . . . . . . . . . . . 343
California
Proposition
65 Warning . . . . . . . . . .343, 369, 426, Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 461
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 264
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . 43
Winter Driving . . . . . . . . . . . . . . . . 245
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . 126
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 183
Caution, Danger, and Warning . . . . 3
CD Player . . . . . . . . . . . . . . . . . . . . . . 195
Center Console Storage . . . . . . . . 125
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 380
Center Seat . . . . . . . . . . . . . . . . . . . . . 59
Chains, Tire . . . . . . . . . . . . . . . . . . . . 413
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 134
Charging System Light . . . . . . . . . 149 Check
Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Ignition Transmission Lock . . . 374
Child Restraints Infants and Young Children . . . . . 94
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . 99
Older Children . . . . . . . . . . . . . . . . . . 92
Securing . . . . . . . . . . . . . 111, 114, 115
Systems . . . . . . . . . . . . . . . . . . . . . . . . 96
Circuit Breakers . . . . . . . . . . . . . . . . 381
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 435
Interior Care . . . . . . . . . . . . . . . . . . 441
Climate Control
Systems . . . . . . . . . . . . . . . . . 224, 226
Air Conditioning . . . . . . . . . 224, 226
Dual Automatic . . . . . . . . . . . . . . . 228
Heating . . . . . . . . . . . . . . . . . . 224, 226
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Cluster, Instrument . . . . . . . . . . . . . 138
Collision Damage Repair . . . . . . . 472
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . 124
Compass . . . . . . . . . . . . . . . . . . . . . . . 131
Connections OnStar . . . . . . . . . . . . . . . . . . . . . . . 482 Control
Hill Descent . . . . . . . . . . . . . . . . . . 284
Traction and Electronic
Stability . . . . . . . . . . . . . . . . . . . . . 282
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 153
Control of a Vehicle . . . . . . . . . . . . . 236
Convex Mirrors . . . . . . . . . . . . . . . . . . 47
Coolant
Engine Temperature Gauge . . 144
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 155
Cooling . . . . . . . . . . . . . . .224, 226, 228
Cooling System . . . . . . . . . . . . . . . . . 359
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . . . 471
Cruise Control . . . . . . . . . . . . . . . . . . 285 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Cupholders . . . . . . . . . . . . . . . . . . . . . 124
Customer Assistance . . . . . . . . . . . 468 Offices . . . . . . . . . . . . . . . . . . . . . . . . 467
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 468
Customer Information Service Publications
Ordering Information . . . . . . . . 474
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 465