check oil GMC SIERRA 2021 User Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
330 Vehicle Care
1. Remote Negative (–) Location. SeeJump
Starting - North America 0391.
2. Positive (+) Terminal (Under Cover). See Jump Starting - North America 0391.
3. Battery - North America 0343.
4. Engine Compartment Fuse Block 0353.
5. Engine Oil Dipstick. See “Checking Engine
Oil” under Engine Oil 0330.
6. Engine Cooling Fans (Out of View). See Cooling System 0335.
7. Engine Oil Fill Cap. See “When to Add
Engine Oil” underEngine Oil 0330.
8. Coolant Surge Tank and Pressure Cap. See Cooling System 0335.
9. Engine Air Cleaner/Filter 0334.
10. Brake Fluid Reservoir. See Brake Fluid
0 343.
11. Windshield Washer Fluid Reservoir. See “Adding Washer Fluid” underWasher
Fluid 0340.
Engine Oil
For diesel engine vehicles, see “Engine Oil”
in the Duramax diesel supplement. To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See
“Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. SeeEngine Oil Life System 0332.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 0325 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle.
If a low oil Driver Information Center (DIC)
message displays, check the oil level.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Vehicle Care 331
When to Add Engine Oil
If the oil is below the cross-hatched area at
the tip of the dipstick and the engine has
been off for at least 15 minutes, add 1 L
(1 qt) of the recommended oil and then
recheck the level. See“Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use. For
engine oil crankcase capacity, see Capacities
and Specifications 0424.
Caution
Do not add too much oil. Oil levels above
or below the acceptable operating range
shown on the dipstick are harmful to the
engine. If the oil level is above the
operating range (i.e., the engine has so
much oil that the oil level gets above the
cross-hatched area that shows the proper
operating range), the engine could be
(Continued)
Caution (Continued)
damaged. Drain the excess oil or limit
driving of the vehicle, and seek a service
professional to remove the excess oil.
See Engine Compartment Overview 0325 for
the location of the engine oil fill cap.
Add enough oil to put the level somewhere
in the proper operating range. Push the
dipstick all the way back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil depends on
both the proper oil specification and
viscosity grade. See Recommended Fluids
and Lubricants 0418.
Specification
Use full synthetic engine oils that meet the
dexos1 specification. Engine oils that have
been approved by GM as meeting the
dexos1 specification are marked with the
dexos1 approved logo.
Caution
Failure to use the recommended engine
oil or equivalent can result in engine
damage not covered by the vehicle
warranty.
Viscosity Grade
Use SAE 0W-20 viscosity grade engine oil for
the 5.3L and 6.2L V8 engines.
Use SAE 5W-30 viscosity grade engine oil for
the 2.7L L4, and 4.3L V6 engines. Cold
Temperature Operation: In an area of
extreme cold, where the temperature falls
below −29 °C (−20 °F), use SAE 0W-30 oil. An
oil of this viscosity grade will provide easier
cold starting for the engine at extremely
low temperatures.
When selecting an oil of the appropriate
viscosity grade, it is recommended to select
an oil of the correct specification. See
“Specification” earlier in this section.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
332 Vehicle Care
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for good
performance and engine protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal.
Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that
indicates when to change the engine oil and
filter. This is based on a combination of
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
On some vehicles, when the system has
calculated that oil life has been diminished,
a CHANGE ENGINE OIL SOON message comes
on to indicate that an oil change is
necessary. Change the oil as soon as
possible within the next 1 000 km (600 mi).
It is possible that, if driving under the best
conditions, the oil life system might indicate
that an oil change is not necessary for up to
a year. The engine oil and filter must be
changed at least once a year and, at this
time, the system must be reset. For vehicles
without the CHANGE ENGINE OIL SOON
message, an oil change is needed when the
REMAINING OIL LIFE percentage is near 0%.
Your dealer has trained service people whowill perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To reset the
engine oil life system:
1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Press the thumbwheel on the steering wheel, or the trip odometer reset stem if
the vehicle does not have DIC controls,
for several seconds. When the
confirmation message displays, select
YES. The oil life will change to 100%.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Vehicle Care 333
The oil life system can also be reset as
follows:1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Fully press the accelerator pedal slowly three times within five seconds.
3. If the display changes to 100%, the system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See
Publication Ordering
Information 0435.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0418.
Change the fluid and filter at the scheduled
maintenance intervals listed in Maintenance
Schedule 0409. Be sure to use the
transmission fluid listed in Recommended
Fluids and Lubricants 0418.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
3. Press
Ton the steering wheel, or press
the trip odometer reset stem if the
vehicle does not have DIC controls, to
move to the Reset/Disable display area.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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336 Vehicle Care
{Warning
Do not touch heater, radiator, a/c pipes
or 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. 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, seeEngine Overheating 0338.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
(Continued)
Warning (Continued)
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. 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, 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 in the engine
compartment on the driver side of the
vehicle. See
Engine Compartment Overview
0 325.
The vehicle must be on a level surface when
checking the coolant level.
All Engines

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Vehicle Care 337
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 indicated 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 indicated mark, see the
following sections on how to add coolant to
the coolant surge tank following.
Automatic Coolant Service Fill
Instructions (L3B Engine)
This feature assists in filling and removing
air from the cooling system after service of
components or when coolant is added after
being too low.
To activate the fill and air removal process: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 indicated mark.
4. Connect the vehicle to a battery charger.
5. Set the ignition to service mode, see Ignition Positions (Keyless Access) 0230
or
Ignition Positions (Key Access) 0229.
6. Turn off the air conditioning.
7. Set the parking brake.
8. At the same time, press the accelerator and the brake for automatic vehicles for
two seconds, then release.
9. Listen for pump activation and movement of the control valves while
watching the level of the coolant in the
surge tank. Add fluid as the level drops
below the indicated mark on the surge
tank. Allow 15 minutes for the fill and air
removal process to complete.
10. Reinstall the surge tank cap.
If the tank empties, turn the ignition off,
allow the Electronic Control Module (ECM) to
go to sleep, about two minutes, refill to the
indicated mark, and repeat Steps 5–9.
How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
Except L3B
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.
{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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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408 Service and Maintenance
Service and Maintenance
General Information
General Information . . . . . . . . . . . . . . . . . . 408
Maintenance Schedule
Maintenance Schedule . . . . . . . . . . . . . . . . 409
Special Application Services
Special Application Services . . . . . . . . . . . . 415
Additional Maintenance and Care
Additional Maintenance and Care . . . . . . 415
Recommended Fluids, Lubricants, and
Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Maintenance Replacement Parts . . . . . . . 419
Maintenance Records
Maintenance Records . . . . . . . . . . . . . . . . . . 422
General Information
This maintenance section applies to vehicles
with a gasoline engine. For diesel engine
vehicles, see "Maintenance Schedule" in the
Duramax diesel supplement.
Your vehicle is an important investment.
This section describes the required
maintenance for the vehicle. Follow this
schedule to help protect against major repair
expenses resulting from neglect or
inadequate maintenance. It may also help to
maintain the value of the vehicle if it is
sold. It is the responsibility of the owner to
have all required maintenance performed.
Your dealer has trained technicians who can
perform required maintenance using genuine
replacement parts. They have up-to-date
tools and equipment for fast and accurate
diagnostics. Many dealers have extended
evening and Saturday hours, courtesy
transportation, and online scheduling to
assist with service needs.
Your dealer recognizes the importance of
providing competitively priced maintenance
and repair services. With trained technicians,
the dealer is the place for routine maintenance such as oil changes and tire
rotations and additional maintenance items
like tires, brakes, batteries, and wiper blades.
Caution
Damage caused by improper maintenance
can lead to costly repairs and may not be
covered by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids, and
lubricants are important to keep the
vehicle in good working condition.
Do not have chemical flushes that are not
approved by GM performed on the
vehicle. The use of flushes, solvents,
cleaners, or lubricants that are not
approved by GM could damage the
vehicle, requiring expensive repairs that
are not covered by the vehicle warranty.
The Tire Rotation and Required Services are
the responsibility of the vehicle owner. It is
recommended to have your dealer perform
these services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to keep
the vehicle in good working condition,
improves fuel economy, and reduces vehicle
emissions.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Service and Maintenance 409
Because of the way people use vehicles,
maintenance needs vary. There may need to
be more frequent checks and services. The
Additional Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire and
Loading Information label. SeeVehicle
Load Limits 0222.
.Are driven on reasonable road surfaces
within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel (Except 6.2L
V8 Engine) 0283 or
Recommended Fuel (6.2L V8 Engine)
0 284.
Refer to the information in the Maintenance
Schedule Additional Required Services -
Normal chart.
The Additional Required Services - Severe are
for vehicles that are:
.Mainly driven in heavy city traffic in hot
weather
.Mainly driven in hilly or mountainous
terrain
.Frequently towing a trailer
.Used for high speed or competitive
driving
.Used for taxi, police, or delivery service
Refer to the information in the Maintenance
Schedule Additional Required Services -
Severe chart.
{Warning
Performing maintenance work can be
dangerous and can cause serious injury.
Perform maintenance work only if the
required information, proper tools, and
equipment are available. If they are not,
see your dealer to have a trained
technician do the work. See Doing Your
Own Service Work 0323.
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. See Engine Oil
0 330.
Once a Month
.Check the tire inflation pressures,
including the spare. See Tire Pressure
0 367.
.Inspect the tires for wear. See Tire
Inspection 0373.
.Check the windshield washer fluid level.
See Washer Fluid 0340.
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 0332.
Engine Air Filter Change
When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the engine
air filter should be replaced at the earliest
convenience. Reset the engine air filter life
system after the engine air filter is replaced.
See Engine Air Filter Life System 0333.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
410 Service and Maintenance
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.
Extended Idle Use
When the vehicle is used in a way that
requires extended idle time, one hour of use
shall be deemed the same as 53 km (33 mi).
SeeDriver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel and
Uplevel) 0125 for hourmeter, if equipped.
Air Conditioning Desiccant (Replace Every
Seven Years)
The air conditioning system requires
maintenance every seven years. This service
requires replacement of the desiccant to
help the longevity and efficient operation of
the air conditioning system. This service can
be complex. See your dealer.
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 0374.
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system.
See Engine Oil 0330 and
Engine Oil Life System 0332.
.If equipped with the engine air filter life
system, check the air filter
life percentage. If necessary, replace the
engine air filter and reset the engine air
filter life system. See Engine Air Filter Life
System 0333. If the vehicle is not
equipped with the engine air filter life
system, inspect the engine air cleaner
filter. See Engine Air Cleaner/Filter 0334.
.Check engine coolant level. See Cooling
System 0335.
.Check windshield washer fluid level. See
Washer Fluid 0340.
.Check tire inflation pressures, including
the spare. See Tire Pressure0367.
.Inspect tire wear. See Tire Inspection
0 373.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior Care
0 398.
.Visually inspect steering, suspension, and
chassis components for damage, including
cracks or tears in the rubber boots, loose
or missing parts, or signs of wear at least
once a year. See Exterior Care0398.
If equipped with grease fittings, lubricate
the suspension and steering components
every other oil change for normal usage
and every oil change for severe usage.
.Inspect power steering for proper
attachment, connections, binding, leaks,
cracks, chafing, etc.
.Visually inspect drive shafts for excessive
wear, lubricant leaks or damage including:
tube dents, cracks, constant velocity joint
or universal joint looseness, cracked or

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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412 Service and Maintenance
Additional Required ServicesMaintenance Schedule Additional
Required Services - Normal
12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires and/or boots.
(2.7L L4 Turbo Engine Only)@ @
Change transfer case fluid, if equipped with 4WD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)