2007 GMC YUKON XL engine overheat

If No Steam Is Coming From Your
Engine
The ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant condition, can
indicate a serious problem.
If you get an engine overheat warning, but see or
hear no steam, the problem may not be too
serious. Sometimes the engine can get a little too
hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on
page 405.If you get the ENGINE OVERHEATED STOP
ENGINE or the ENGINE OVERHEATED IDLE
ENGINE message with no sign of steam, try this
for a minute or so:
1. If you have an air conditioner and it is on,
turn it off.
2. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
3. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to
do so, pull off the road, shift to PARK (P)
or NEUTRAL (N) and let the engine idle.
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.
If the warning continues, pull over, stop, and park
your vehicle immediately.
453

If there is still no sign of steam and your 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 ve minutes while you are parked.
If there is still no sign of steam and your vehicle is
equipped with an electric cooling fan, idle the
engine for ve minutes while you are parked.
If you still have the warning, turn off the engine
and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine
Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is
displayed, an overheat protection mode which
alternates ring groups of cylinders helps prevent
engine damage. In this mode, you will notice a
loss in power and engine performance. This
operating mode allows your vehicle to be driven to
a safe place in an emergency. Driving extended
miles (km) 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. SeeEngine Oil on page 438.
454

Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s){CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
If possible, the vehicle should be parked on a
level surface. Check the coolant level after
the system cools down. Some amount of coolant
may be lost due to overheating.
5.3L Engine (4.8L and 6.0L Similar)
455

The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak at
the pressure cap or in the radiator hoses,
heater hoses, radiator, water pump or somewhere
else in the cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
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 re,
and you could be burned. Get any leak
xed before you drive the vehicle.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 454for information on
driving to a safe place in an emergency.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core or
radiator corrosion. In addition, the engine
coolant may require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
456

{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and
crack the engine, radiator, heater core and
other parts. Use the recommended coolant and
the proper coolant mixture.
{CAUTION:
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.
1. You can 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 you hear a hiss, wait
for that to stop. A hiss means there is
still some pressure left.
458

Driver Information Center (DIC).................... 244
DIC Operation and Displays..............244, 251
DIC Vehicle Customization........................ 264
DIC Warnings and Messages.................... 254
Driving
At Night.................................................... 373
City........................................................... 378
Defensive.................................................. 340
Drunken.................................................... 341
Freeway.................................................... 379
Hill and Mountain Roads........................... 382
In Rain and on Wet Roads....................... 375
Off-Road................................................... 356
Recovery Hooks....................................... 389
Rocking Your Vehicle to Get it Out........... 388
Winter....................................................... 384
Dual Automatic Climate Control System........ 213
DVD
Rear Seat Entertainment System.............. 321
E
Electrical System
Add-On Equipment.................................... 539
Center Instrument Panel Fuse Block......... 542
Fuses and Circuit Breakers....................... 540
Instrument Panel Fuse Block.................... 540Electrical System (cont.)
Power Windows and Other
Power Options....................................... 539
Underhood Fuse Block.............................. 543
Windshield Wiper Fuses............................ 539
Engine
Air Cleaner/Filter....................................... 443
Battery...................................................... 466
Check and Service Engine Soon Light...... 236
Coolant..................................................... 449
Coolant Heater.......................................... 140
Coolant Temperature Gage....................... 234
Drive Belt Routing..................................... 567
Engine Compartment Overview................. 436
Exhaust.................................................... 155
Fan Noise................................................. 460
Oil ............................................................ 438
Oil Life System......................................... 441
Overheated Protection Operating Mode....... 454
Overheating.............................................. 452
Starting..................................................... 138
Entry Lighting............................................... 204
Event Data Recorders (EDR)....................... 583
Exit Lighting................................................. 204
Extender, Safety Belt...................................... 60
Exterior Lamps............................................. 199
597

Oil
Engine...................................................... 438
Pressure Gage.......................................... 239
Pressure Light.......................................... 240
Oil, Engine Oil Life System.......................... 441
Older Children, Restraints.............................. 61
Online Owner Center................................... 574
OnStar
®System, see OnStar®Manual......... 167
Other Warning Devices................................ 188
Outlet Adjustment......................................... 220
Outlet(s), Accessory Power........................... 208
Outside
Automatic Dimming Mirror......................... 166
Convex Mirror........................................... 166
Curb View Assist Mirrors........................... 166
Heated Mirrors.......................................... 167
Manual Mirrors.......................................... 163
Power Foldaway Mirrors............................ 165
Power Mirrors........................................... 164
Trailer-Tow Mirrors.................................... 163
Overheated Engine Protection
Operating Mode........................................ 454
Owner Checks and Services........................ 560
Owners, Canadian........................................... 3
P
Paint, Damage............................................. 536
Park Aid....................................................... 205
Park (P)
Shifting Into.............................................. 152
Shifting Out of.......................................... 154
Parking
Assist....................................................... 205
Brake........................................................ 151
Over Things That Burn............................. 154
Passenger Airbag Status Indicator................ 228
Passenger Sensing System.......................... 100
Passing........................................................ 353
PASS-Key
®III+............................................ 134
PASS-Key®III+ Operation............................ 134
Power
Accessory Outlet(s)................................... 208
Door Locks............................................... 121
Electrical System...................................... 539
Liftgate..................................................... 125
Lumbar Controls......................................... 11
Retained Accessory (RAP)........................ 138
Running Boards........................................ 129
Seat........................................................... 10
602