2018 GMC YUKON engine overheat

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
296 Vehicle Care
What to Use
{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.
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
temperatureCaution
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
passenger side of the vehicle. See
Engine Compartment Overview
0 284.
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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 297
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,” following.
How to Add Coolant to the
Coolant Surge Tank
{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
(Continued)
Warning (Continued)
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.
Caution
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.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
298 Vehicle Care
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 engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating
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 0141.
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
0 396.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Check to see if the engine cooling
fan(s) are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine. Have the
vehicle serviced.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 299
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.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
0 266.
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 engine coolant temperature
gauge is no longer in the overheat
zone or an overheat warning no
longer 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Index 421
Driving (cont'd)Defensive . . . . . . . . . . . . . . . . . . . . . 194
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 194
For Better Fuel Economy . . . . . . . 27
Hill and Mountain Roads . . . . . . 202
If the Vehicle is Stuck . . . . . . . . . 203
Loss of Control . . . . . . . . . . . . . . . 196
Off-Road . . . . . . . . . . . . . . . . . . . . . 196
Off-Road Recovery . . . . . . . . . . . 195
Vehicle Load Limits . . . . . . . . . . . 204
Wet Roads . . . . . . . . . . . . . . . . . . . 201
Winter . . . . . . . . . . . . . . . . . . . . . . . . 202
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 184
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 260
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 279
Electrical System Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 314
Fuses and Circuit Breakers . . . 313
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 318, 321
Overload . . . . . . . . . . . . . . . . . . . . . 313
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 323 Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . 407
Engine Air Cleaner/Filter . . . . . . . . . . . . . 294
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 146
Compartment Overview . . . . . . . 284
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 141
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 151
Cooling System . . . . . . . . . . . . . . . 295
Drive Belt Routing . . . . . . . . . . . . 391
Exhaust . . . . . . . . . . . . . . . . . . . . . . 219
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Heater . . . . . . . . . . . . . . . . . . . . . . . . 215
Oil Life System . . . . . . . . . . . . . . . 289
Oil Pressure Gauge . . . . . . . . . . 140
Oil Pressure Light . . . . . . . . . . . . 152
Overheating . . . . . . . . . . . . . . . . . . 298
Power Messages . . . . . . . . . . . . . 161
Running While Parked . . . . . . . . 220
Starting . . . . . . . . . . . . . . . . . . . . . . . 213
Entry Lighting . . . . . . . . . . . . . . . . . . . 181
Equipment, Towing . . . . . . . . . . . . . 271
Event Data Recorders . . . . . . . . . . 404
Exit Lighting . . . . . . . . . . . . . . . . . . . . 181
Extended Parking . . . . . . . . . . . . . . . 219 Extender, Seat Belt . . . . . . . . . . . . . . 85
Exterior Lamp Controls . . . . . . . . . 174
Exterior Lamps Off Reminder . . . 176
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . . . 182
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 300
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter,
Engine Air Cleaner . . . . . . . . . . . 294
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 176
Flashers, Hazard Warning . . . . . . 178
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 345 Changing . . . . . . . . . . . . . . . . . . . . . 346
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 373
Fluid AutomaticTransmission . . . . . . . . . . . 290, 293
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 302
Four-Wheel Drive Transfer Case . . . . . . . . . . . . . . . 226
Washer . . . . . . . . . . . . . . . . . . . . . . . 300
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 179

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Index 425
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . 139Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 196 Driving . . . . . . . . . . . . . . . . . . . . . . . . 196
Recovery . . . . . . . . . . . . . . . . . . . . . 195
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 287
Engine Oil Life System . . . . . . . 289
Engine Oil Pressure Gauge . . . 140
Pressure Light . . . . . . . . . . . . . . . . 152
Older Children, Restraints . . . . . . 100
Online Owner Center . . . . . . . . . . . 395
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . 405
OnStar Additional Information . . . . . . . . . . . . . . . . . . . . 412
OnStar Connections . . . . . . . . . . . . 409
OnStar Diagnostics . . . . . . . . . . . . . 411
OnStar Emergency . . . . . . . . . . . . . 407
OnStar Navigation . . . . . . . . . . . . . . 408
OnStar Overview . . . . . . . . . . . . . . . 406
OnStar Security . . . . . . . . . . . . . . . . 408
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . 179
Ordering Service Publications . . . . . . . . . . 401
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . 130 Overheating, Engine . . . . . . . . . . . . 298P
Park
Shifting Into . . . . . . . . . . . . . . . . . . . 217
Shifting Out of . . . . . . . . . . . . . . . . 218
Parking
Brake . . . . . . . . . . . . . . . . . . . . . . . . . 232
Brake and P (Park)Mechanism Check . . . . . . . . . . 307
Extended . . . . . . . . . . . . . . . . . . . . . 219
Over Things That Burn . . . . . . . 218
Parking Assist . . . . . . . . . . . . . . . . . . 248
Parking or Backing Assistance Systems . . . . . . . . . . 248
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . 145
Passenger Compartment Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Passenger Sensing System . . . . . 93
Perchlorate Materials Requirements, California . . . . . . 282
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 162
Power Door Locks . . . . . . . . . . . . . . . . . . . . . 43
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Outlets . . . . . . . . . . . . . . . . . . . . . . . 130 Power (cont'd)
Protection, Battery . . . . . . . . . . . . 182
Retained Accessory (RAP) . . . 216
Seat Adjustment . . . . . . . . . . . . . . . . 64
Windows . . . . . . . . . . . . . . . . . . . . . . . 58
Power Assist Steps . . . . . . . . . . . . . . 50
Pregnancy, Using Seat Belts . . . . 84
Privacy Vehicle Data Recording . . . . . . . 404
Program Courtesy Transportation . . . . . . 398
Proposition 65 Warning,
California . . . . . . . . . . . .281, 303, 356, Back Cover
R
Radio Frequency Statement . . . . 402
Reading Lamps . . . . . . . . . . . . . . . . . 180
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . 305Locking . . . . . . . . . . . . . . . . . . . . . . . 237
Rear Climate Control System . . . 188
Rear Seats . . . . . . . . . . . . . . . . . . . . . . 70 Heated . . . . . . . . . . . . . . . . . . . . . . . . . 71
Rear Storage . . . . . . . . . . . . . . . . . . . 122
Rear Vision Camera (RVC) . . . . . 248
Rear Window Washer/Wiper . . . . 128
Rearview Mirrors . . . . . . . . . . . . . . . . 57