2011 GMC SIERRA cooling

Black plate (20,1)GMC Sierra Owner Manual - 2011
10-20 Vehicle Care
Replacing the Engine Air
Cleaner/Filter
1. Locate the air cleaner/filterassembly. See Engine
Compartment Overview on
page 10‑6.
2. Loosen the four screws on the cover of the housing and lift up
the cover.
3. Remove the engine aircleaner/filter from the housing.
Take care to dislodge as little
dirt as possible.
4. Clean the engine air cleaner/filter sealing surfaces
and the housing.
5. Inspect or replace the engine air cleaner/filter.
6. Reinstall the cover and tighten the screws.
{WARNING
Operating the engine with the air
cleaner/filter off can cause you
or others to be burned. The air
cleaner not only cleans the air;
it helps to stop flames if the
engine backfires. Use caution
when working on the engine
and do not drive with the air
cleaner/filter off.
Cooling System
If the vehicle has the Duramax®
Diesel engine, see the Duramax®
Diesel Supplement for more
information.
The cooling system allows the
engine to maintain the correct
working temperature.

Black plate (21,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-21
5.3 L Engine Shown (4.3 L, 4.8 L,6.0 L and, 6.2 L Engines Similar)
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan (Out of View)
{WARNING
An electric engine cooling fan
can start even when the engine
is not running. To avoid injury,
always keep hands, clothing,
and tools away from any engine
cooling fan.
{WARNING
Heater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
(Continued)
WARNING (Continued)
Do not run the engine if there is
a leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
Notice: Using coolant other than
DEX-COOL
®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner, at 50 000 km (30,000 mi)
or 24 months, whichever occurs
first. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL
(silicate-free) coolant in the
vehicle.

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.

Black plate (24,1)GMC Sierra Owner Manual - 2011
10-24 Vehicle Care
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
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Notice: This vehicle has a
specific coolant fill procedure.
Failure to follow this procedure
could cause the engine to
overheat and be severely
damaged.
{WARNING
An electric engine cooling fan
under the hood 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
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. They are
under pressure, and if you turn
the coolant surge tank pressure
cap —even a little —they can
come out at high speed. Never
turn the cap when the cooling
system, including the coolant
surge tank pressure cap, is hot.
Wait for the cooling system and
coolant surge tank pressure cap
to cool if you ever have to turn
the pressure cap. If no coolant is visible in the surge
tank, add coolant as follows:
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.

Black plate (25,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-25
3. Fill the coolant surge tankwith 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. Be sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 through 6.
Notice: If the pressure cap is
not tightly installed, coolant loss
and possible 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 for more
information.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on the vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑17.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC) on the
instrument panel. See Engine
Cooling System Messages on
page 5‑44 andEngine Power
Messages on page 5‑45.

Black plate (26,1)GMC Sierra Owner Manual - 2011
10-26 Vehicle Care
If the decision is made not to lift the
hood when this warning appears,
get service help right away.
SeeRoadside Assistance Program
(U.S. and Canada) on page 13‑8
or Roadside Assistance Program
(Mexico) on page 13‑10.
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 fans are running. If the
engine is overheating, both fans
should be running. If they are not,
do not continue to run the engine
and have the vehicle serviced.
Notice: Engine damage from
running your engine without
coolant is not covered by the
vehicle warranty. See Overheated
Engine Protection Operating
Mode for information on driving
to a safe place in an emergency. Notice:
If the engine catches fire
while driving with no coolant, the
vehicle can be badly damaged.
The costly repairs would not
be covered by the vehicle
warranty. See Overheated Engine
Protection Operating Mode on
page 10‑28 for information on
driving to a safe place in an
emergency.
If Steam is Coming from the
Engine Compartment
{WARNING
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or
hear steam coming from it.
Turn it off and get everyone
away from the vehicle until it
cools down. Wait until there
is no sign of steam or coolant
before you open the hood.
(Continued)
WARNING (Continued)
If you keep driving when the
vehicles engine is overheated,
the liquids in it can catch fire.
You or others could be badly
burned. Stop the engine if it
overheats, and get out of the
vehicle until the engine is cool.
SeeOverheated Engine
Protection Operating Mode on
page 10‑28 for information on
driving to a safe place in an
emergency.

Black plate (28,1)GMC Sierra Owner Manual - 2011
10-28 Vehicle Care
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage.
In this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe
place in an emergency. Driving
extended km (mi) and/or towing a
trailer in the overheat protection
mode should be avoided.
Notice:After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause
of coolant loss, change the oil
and reset the oil life system.
See Engine Oil on page 10‑7.
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
fans, 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.