2016 GMC SIERRA engine overheat

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
374 Vehicle Care
Checking Coolant
The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment
Overview0358.
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, 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.
5.3L V8 Shown, 4.3L V6, 6.0L V8,
and 6.2L V8 Similar
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
(Continued)
Warning (Continued)
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
Caution
This vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.
If no coolant is visible in the surge
tank, add coolant.

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Vehicle Care 375
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.
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
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.
Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
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 0135.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC). See
Engine Cooling System Messages
0 154 andEngine Power
Messages 0155.

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
376 Vehicle Care
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance
Program0476.
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 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. Just turn it (Continued)
Warning (Continued)
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.
If you keep driving when the
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.
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. If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.
Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer
Towing 0325.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Vehicle Care 377
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.
If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.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
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before(Continued)
Caution (Continued)
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil 0363.
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.

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Index 499
D
Damage Repair, Collision . . . . . . . 479
Danger, Warning, and Caution . . . . 3
Data Recorders, Event . . . . . . . . . 484
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . . . 177
Defensive Driving . . . . . . . . . . . . . . . 258
Delayed Locking . . . . . . . . . . . . . . . . . 39
Diagnostics OnStar
®. . . . . . . . . . . . . . . . . . . . . . 490
Distracted Driving . . . . . . . . . . . . . . . 257
Dome Lamps . . . . . . . . . . . . . . . . . . . 181
Door Ajar Messages . . . . . . . . . . . . . . . 154
Delayed Locking . . . . . . . . . . . . . . . . 39
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Power Locks . . . . . . . . . . . . . . . . . . . . 39
Drive Belt Routing, Engine . . . . . . 471
Driver Assistance Systems . . . . . 309
Driver Information Center (DIC) . . . . . . . . . . . . . 148, 150
Driving Assistance Systems . . . . . . . . . . 312
Characteristics andTowing Tips . . . . . . . . . . . . . . . . . 322
Defensive . . . . . . . . . . . . . . . . . . . . . 258
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 258
For Better Fuel Economy . . . . . . . 30 Driving (cont'd)
Hill and Mountain Roads . . . . . . 266
If the Vehicle is Stuck . . . . . . . . . 268
Loss of Control . . . . . . . . . . . . . . . 260
Off-Road . . . . . . . . . . . . . . . . . . . . . 261
Off-Road Recovery . . . . . . . . . . . 260
Vehicle Load Limits . . . . . . . . . . . 269
Wet Roads . . . . . . . . . . . . . . . . . . . 265
Winter . . . . . . . . . . . . . . . . . . . . . . . . 267
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 250
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 319
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 349
Electrical System Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 392
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 392
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 395, 397
Overload . . . . . . . . . . . . . . . . . . . . . 391
Emergency
OnStar
®. . . . . . . . . . . . . . . . . . . . . . 487
Engine Air Cleaner/Filter . . . . . . . . . . . . . 370
Check and Service EngineSoon Light . . . . . . . . . . . . . . . . . . 141 Engine (cont'd)
Compartment Overview . . . . . . . 358
Coolant . . . . . . . . . . . . . . . . . . . . . . . 373
Coolant Heater . . . . . . . . . . . . . . . 281
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 135
Cooling System . . . . . . . . . . . . . . . 371
Cooling System Messages . . . 154
Drive Belt Routing . . . . . . . . . . . . 471
Exhaust . . . . . . . . . . . . . . . . . . . . . . 285
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 377
Oil Life System . . . . . . . . . . . . . . . 366
Oil Messages . . . . . . . . . . . . . . . . . 155
Oil Pressure Gauge . . . . . . . . . . 134
Overheated Protection Operating Mode . . . . . . . . . . . . . 377
Overheating . . . . . . . . . . . . . . . . . . 375
Power Messages . . . . . . . . . . . . . 155
Running While Parked . . . . . . . . 286
Starting . . . . . . . . . . . . . . . . . . . . . . . 279
Entry Lighting . . . . . . . . . . . . . . . . . . . 182
Equipment, Towing . . . . . . . . . . . . . 339
Event Data Recorders . . . . . . . . . . 484
Exit Lighting . . . . . . . . . . . . . . . . . . . . 182
Extender, Safety Belt . . . . . . . . . . . . 70
Exterior Lamp Controls . . . . . . . . . 174
Exterior Lamps Off Reminder . . . 176

GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234758) - 2016 - crc - 11/9/15
Index 503
Messages (cont'd)Engine Oil . . . . . . . . . . . . . . . . . . . . 155
Engine Power . . . . . . . . . . . . . . . . 155
Fuel System . . . . . . . . . . . . . . . . . . 156
Key and Lock . . . . . . . . . . . . . . . . . 156
Lamp . . . . . . . . . . . . . . . . . . . . . . . . . 156
Object Detection System . . . . . 156
Ride Control System . . . . . . . . . . 157
Safety Belt . . . . . . . . . . . . . . . . . . . . 158
Security . . . . . . . . . . . . . . . . . . . . . . 159
Steering System . . . . . . . . . . . . . . 159
Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Transmission . . . . . . . . . . . . . . . . . 160
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 153
Vehicle Reminder . . . . . . . . . . . . . 162
Vehicle Speed . . . . . . . . . . . . . . . . 162
Washer Fluid . . . . . . . . . . . . . . . . . 163
Mirrors
Automatic Dimming . . . . . . . . . . . . . 48
Automatic DimmingRearview . . . . . . . . . . . . . . . . . . . . . . 50
Blind Spot . . . . . . . . . . . . . . . . . . . . . . 48
Convex . . . . . . . . . . . . . . . . . . . . . . . . . 45
Folding . . . . . . . . . . . . . . . . . . . . . . . . . 47
Heated . . . . . . . . . . . . . . . . . . . . . . . . . 48
Manual Rearview . . . . . . . . . . . . . . . 49
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Tilt in Reverse . . . . . . . . . . . . . . . . . . 49 Mirrors (cont'd)
Trailer Tow . . . . . . . . . . . . . . . . . . . . . . 46
Mirrors, Interior Rearview . . . . . . . . 49
Monitor System, Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 409
Multi-band Antenna . . . . . . . . . . . . . 199
N
Navigation OnStar®. . . . . . . . . . . . . . . . . . . . . . 487
New Vehicle Break-In . . . . . . . . . . . 277
Noise Control System . . . . . . . . . . 385
O
Object Detection System Messages . . . . . . . . . . . . . . . . . . . . . 156
Odometer . . . . . . . . . . . . . . . . . . . . . . . 133 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 261 Driving . . . . . . . . . . . . . . . . . . . . . . . . 261
Recovery . . . . . . . . . . . . . . . . . . . . . 260
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 363
Engine Oil Life System . . . . . . . 366
Engine Oil Pressure Gauge . . . 134
Messages . . . . . . . . . . . . . . . . . . . . 155
Older Children, Restraints . . . . . . . 87
Online Owner Center . . . . . . . . . . . 475
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . 485 OnStar
®Additional
Information . . . . . . . . . . . . . . . . . . . . 490
OnStar
®Connections . . . . . . . . . . . 488
OnStar®Diagnostics . . . . . . . . . . . . 490
OnStar®Emergency . . . . . . . . . . . . 487
OnStar®Navigation . . . . . . . . . . . . . 487
OnStar®Overview . . . . . . . . . . . . . . 486
OnStar®Security . . . . . . . . . . . . . . . 487
Operating Mode Overheated EngineProtection . . . . . . . . . . . . . . . . . . . 377
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . 179
Ordering Service Publications . . . . . . . . . . 481
Outlets
Power . . . . . . . . . . . . . . . . . . . . . . . . 126
Overheated Engine Protection Operating Mode . . . . 377
Overheating, Engine . . . . . . . . . . . . 375
Overview . . . . . . . . . . . . . . . . . . 186, 189
P
Pandora Internet Radio . . . . . . . . . 199
Park Shifting Into . . . . . . . . . . . . . . . . . . . 283
Shifting Out of . . . . . . . . . . . . . . . . 284
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . 301