
Black plate (9,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-9
Selecting the Right Engine Oil
Selecting the right engine oil
depends on both the proper oil
specification and viscosity grade:
Specification
Use and ask for engine oils with
the dexos™certification mark.
Oils meeting the requirements
of the vehicle should have the
dexos certification mark on the
container. This certification mark
indicates that the oil has been
approved to the dexos specification.
This vehicle was filled at the factory
with dexos‐approved engine oil.
Notice: Use only engine oil
that is approved to the dexos
specification or an equivalent
engine oil of the appropriate
viscosity grade. Engine oils
approved to the dexos
specification will show the
dexos symbol on the container. Failure to use the recommended
engine oil or equivalent can
result in engine damage not
covered by the vehicle warranty.
If you are unsure whether the
oil is approved to the dexos
specification, ask your service
provider.
Use of Substitute Engine Oils if
dexos is unavailable: In the event
that dexos‐approved engine oil is
not available at an oil change or
for maintaining proper oil level,
you may use substitute engine oil
displaying the API Starburst symbol
and of SAE 5W-30 viscosity grade.

Black plate (10,1)GMC Sierra Owner Manual - 2011
10-10 Vehicle Care
Use of oils that do not meet the
dexos specification, however, may
result in reduced performance under
certain circumstances.
Viscosity Grade
SAE 5W-30 is the best viscosity
grade for the vehicle. Do not
use other viscosity oils such as
SAE 10W‐30, 10W‐40, or 20W-50.Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below−29°C
(−20°F), an SAE 0W-30 oil
should be used. 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, be
sure to always select an oil that
meets the required specification,
dexos. See “Specification” earlier
in this section for more information.

Black plate (11,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-11
Engine Oil Additives/Engine
Oil Flushes
Do not add anything to the oil.
The recommended oils with the
dexos specification and displaying
the dexos certification mark 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 engine revolutions and engine
temperature, and not on mileage.
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. SeeEngine Oil
Messages on page 5‑45. Change
the oil as soon as possible within
the next 1 000 km (600 miles).

Black plate (12,1)GMC Sierra Owner Manual - 2011
10-12 Vehicle Care
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 OIL LIFE
REMAINING percentage is near
0%. Your dealer has trained service
people who will 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 miles)
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 system on most
vehicles:
1. Display the OIL LIFEREMAINING on the DIC.
If the vehicle does not have
DIC buttons, the vehicle must
be in P (Park) to access this
display. See Driver Information
Center (DIC) on page 5‑33.
2. Press and hold the SET/RESET button on the DIC, or the
trip odometer reset stem
if the vehicle does not have
DIC buttons, for more than
five seconds. The oil life will
change to 100%. On all vehicles, the Engine Oil Life
System can be reset as follows:
1. Turn the ignition to ON/RUN with
the engine off.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the OIL LIFE REMAINING on the DIC.
If the display shows 100%,
the system is reset. See Driver
Information Center (DIC) on
page 5‑33.
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 REMAINING is near 0%,
the engine oil life system has not
been reset. Repeat the procedure.

Black plate (13,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-13
Automatic
Transmission Fluid
(4-Speed Transmission)
When to Check and Change
Automatic Transmission Fluid
A good time to check the automatic
transmission fluid level is when the
engine oil is changed.
Change the fluid and filter at
the intervals listed inScheduled
Maintenance on page 11‑2 and be
sure to use the transmission fluid
listed in Recommended Fluids and
Lubricants on page 11‑8.
How to Check Automatic
Transmission Fluid
Because this operation can be a
little difficult, it may be best to have
this done at the dealer service
department.
If not taken to the dealer, be sure to
follow all the instructions here or a
false reading on the dipstick could
result.
Notice: Too much or too
little fluid can damage the
transmission. Too much can
mean that some of the fluid could
come out and fall on hot engine
parts or exhaust system parts,
starting a fire. Too little fluid
could cause the transmission
to overheat. Be sure to get an
accurate reading if checking
the transmission fluid. Wait at least 30 minutes before
checking the transmission fluid
level if you have been driving:.When outside temperatures are
above 32°C (90°F).
.At high speed for quite a while.
.In heavy traffic
—especially in
hot weather.
.While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by
driving about 24 km (15 miles) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
moves and then remains steady for
10 minutes.

Black plate (19,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-19
5. Safe operating level is within theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level
is low, add only enough fluid
to bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pint). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way,
then flip the handle down to
lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Engine Air Cleaner/Filter
If the vehicle has a diesel engine,
see “Pickup Models” under“Engine
Air Cleaner/Filter” in the Duramax
®
Diesel Supplement for the correct
inspection and replacement
procedures.
SeeEngine Compartment Overview
on page 10‑6 for the location of the
engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at
the scheduled maintenance
intervals and replace it at the first
oil change after each 80 000 km
(50,000 mi) interval. See Scheduled
Maintenance on page 11‑2 for more
information. If driving on dusty/dirty
conditions, inspect the filter at each
engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the engine air cleaner/
filter from the vehicle by following
Steps 1 through 6. When the engine
air cleaner/filter is removed, lightly
shake it to release loose dust and
dirt. If the engine air cleaner/filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter.

Black plate (22,1)GMC Sierra Owner Manual - 2011
10-22 Vehicle Care
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,
see Engine Overheating on
page 10‑25.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is
set for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
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. 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
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.

Black plate (23,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-23
Notice:If extra inhibitors
and/or additives are used in
the vehicle cooling system,
the vehicle could be damaged.
Use only the proper mixture of
the engine coolant listed in this
manual for the cooling system.
See Recommended Fluids and
Lubricants on page 11‑8 for more
information.
Never dispose of engine coolant
by putting it in the trash, 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
on page 10‑6 for more information
on location.
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 is not at
or above the FULL COLD mark, add
a 50/50 mixture of clean, drinkable
water and DEX-COOL coolant at the
coolant surge tank, but be sure the
cooling system is cool before this
is done.
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.