overheating GMC YUKON DENALI 2008 User Guide

Adding Coolant
If more coolant is needed, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool.
{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.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
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.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
Engine Overheating
There is a coolant temperature gage on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-41.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the Driver
Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 3-56.
5-26

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{CAUTION:
An electric engine cooling fan under the hood
can start up even when the engine is not
running and can injure you. 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. 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.
5-29

Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your vehicle Warranty
booklet for details.
{CAUTION:
Poorly maintained and improperly
used tires are dangerous.
Overloading your tires can cause
overheating as a result of too much
exing. You could have an air-out and
a serious accident. SeeLoading Your
Vehicle on page 4-34.
Underinated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your tires are cold. SeeInflation - Tire
Pressure on page 5-60.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to
be cut, punctured, or broken by a
sudden impact — such as when you
hit a pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents.
If your tread is badly worn, or if
your tires have been damaged,
replace them.
SeeHigh-Speed Operation on page 5-62
for ination pressure adjustment for high
speed driving.
20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use.
The low-prole, wide tread design is not
recommended for off-road driving. SeeOff-Road
Driving on page 4-13, for additional information.
5-55

Engine
Air Cleaner/Filter.........................................5-17
Check and Service Engine Soon Light............3-42
Coolant......................................................5-23
Coolant Heater............................................2-29
Coolant Temperature Gage...........................3-41
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-38
Fan Noise..................................................5-34
Oil .............................................................5-13
Oil Life System...........................................5-16
Overheated Protection Operating Mode...........5-28
Overheating................................................5-26
Running While Parked..................................2-39
Starting......................................................2-27
Entry Lighting.................................................3-20
Event Data Recorders.....................................7-16
Exit Lighting...................................................3-20
Extender, Safety Belt.......................................1-48
Exterior Lamps...............................................3-16
F
Filter
Engine Air Cleaner......................................5-17
Finish Damage.............................................5-105
Flashers, Hazard Warning.................................. 3-6Flash-to-Pass................................................... 3-9
Flat Tire........................................................5-77
Flat Tire, Changing.........................................5-78
Flat Tire, Storing.............................................5-94
Fluid.............................................................5-20
Power Steering...........................................5-34
Windshield Washer......................................5-35
Fog Lamp
Fog ...........................................................3-19
Fog Lamp Light..............................................3-47
Front Axle......................................................5-47
Front Reading Lamps......................................3-20
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-9
Filling the Tank............................................. 5-7
Fuels in Foreign Countries.............................. 5-6
Gage.........................................................3-48
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-5
Low Warning Light.......................................3-48
Fuses
Center Instrument Panel Fuse Block.............5-110
Fuses and Circuit Breakers.........................5-108
Instrument Panel Fuse Block.......................5-109
Underhood Fuse Block...............................5-111
Windshield Wiper.......................................5-108
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