fuel GMC YUKON XL 2007 Owner's Guide

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your
vehicle can affect the airow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
The 8th digit of your vehicle identication number
(VIN) shows the code letter or number that
identies your engine. You will nd the VIN at the
top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 538.
If your vehicle has the 5.3L V8 engine
(VIN Code 0) or the 5.3L V8 engine (VIN Code 3),
you may use either regular unleaded gasoline
or ethanol fuel containing up to 85% ethanol (E85);
also seeFuel E85 (85% Ethanol) on page 430.
In all other engines, use only regular unleaded
gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you may notice an audible
knocking noise when you drive, commonly referred
to as spark knock. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, your engine
needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 429for additional information.
428

California Fuel
If your vehicle is certied to meet California
Emissions Standards, it is designed to operate on
fuels that meet California specications. See
the underhood emission control label. If this fuel is
not available in states adopting California
emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal
specications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction Indicator
Lamp on page 236. If this occurs, return to
your authorized GM dealer for diagnosis. If it is
determined that the condition is caused by the type
of fuel used, repairs may not be covered by
your warranty.
Additives
To provide cleaner air, all gasolines in the United
States are now required to contain additives
that will help prevent engine and fuel system
deposits from forming, allowing your emission
control system to work properly. In most cases,
you should not have to add anything to your fuel.
However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations.
To help keep fuel injectors and intake valves clean,
or if your vehicle experiences problems due to
dirty injectors or valves, look for gasoline that is
advertised as TOP TIER Detergent Gasoline. Also,
your GM dealer has additives that will help
correct and prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers
and ethanol, and reformulated gasolines may be
available in your area. General Motors
recommends that you use these gasolines if they
comply with the specications described earlier.
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However, E85 (85% ethanol) and other fuels
containing more than 10% ethanol must not be
used in vehicles that were not designed for
those fuels.
Notice:Your vehicle was not designed for
fuel that contains methanol. Do not use
fuel containing methanol. It can corrode metal
parts in your fuel system and also damage
the plastic and rubber parts. That damage
would not be covered under your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT.
General Motors recommends against the use of
such gasolines. Fuels containing MMT can reduce
the life of spark plugs and the performance of
the emission control system may be affected.
The malfunction indicator lamp may turn on. If this
occurs, return to your authorized GM dealer for
service.Fuel E85 (85% Ethanol)
The 8th digit of your vehicle identication number
(VIN) shows the code letter or number that
identies your engine. You will nd the VIN at the
top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 538.
If your vehicle has the 5.3L V8 engine (Code 0) or
the 5.3L V8 engine (Code 3), you may use
either regular unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85); also seeFuel
on page 428. In all other engines, use only the
unleaded gasoline described underGasoline
Octane on page 428.
Only vehicles that have the 5.3L V8 engine
(Code 0) or the 5.3L V8 engine (Code 3) may use
85% ethanol fuel (E85). General Motors
encourages the use of E85 in vehicles that are
designed to use it. The ethanol in E85 is a
“renewable” fuel, meaning it is made from
renewable sources such as corn and other crops.
Many service stations will not have an 85% ethanol
fuel (E85) pump available. The U. S. Department
of Energy has an alternative fuels website
(http://www.eere.energy.gov/afdc/infrastructure/
locator.html) that can help you nd E85 fuel.
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Those stations that do have E85 should have a
label indicating ethanol content. Do not use the fuel
if the ethanol content isgreaterthan 85%.
At a minimum, E85 should meet ASTM
Specication D 5798.
To ensure quick starts in the wintertime, the
E85 fuel must be formulated properly for your
climate according to ASTM specication D 5798.
If you have trouble starting on E85, it may be
because your E85 fuel is not properly formulated
for your climate. If this happens, switching to
gasoline or adding gasoline to your fuel tank may
improve starting. For good starting and heater
efficiency below 32°F (0°C), the fuel mix in the fuel
tank should contain no more than 70% ethanol.
It is best not to alternate repeatedly between
gasoline and E85. If you do switch fuels, it is
recommended that you add as much fuel as
possible — do not add less than ve gallons
(18.9 L) when refueling. You should drive the
vehicle immediately after refueling for at least
ve miles (8 km).
E85 has less energy per gallon than gasoline, so
you will need to rell your fuel tank more often
when using E85 than when you are using gasoline.
Regular unleaded gasoline is recommendedwhen pulling a trailer. For payload capacity with
ethanol fuel, seeLoading Your Vehicle on
page 390.
Notice:Some additives are not compatible
with E85 fuel and may harm your fuel system.
Damage caused by additives would not be
covered by your new vehicle warranty. Do not
use additives with E85 fuel.
Notice:Your vehicle was not designed for
fuel that contains methanol. Do not use
fuel containing methanol. It can corrode metal
parts in your fuel system and also damage
the plastic and rubber parts. That damage
would not be covered under your warranty.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be
hard to nd. Never use leaded gasoline or any other
fuel not recommended in the previous text on fuel.
Costly repairs caused by use of improper fuel would
not be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business
in the country where you will be driving.
431

Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re
can cause bad injuries. To help avoid
injuries to you and others, read and follow
all the instructions on the pump island.
Turn off your engine when you are
refueling. Do not smoke if you are near
fuel or refueling your vehicle. Keep
sparks, ames, and smoking materials
away from fuel. Do not leave the fuel
pump unattended when refueling your
vehicle — this is against the law in some
places. Keep children away from the fuel
pump; never let children pump fuel.The tethered fuel cap is located behind a hinged
fuel door on the driver’s side of the vehicle.
To open the fuel door, apply pressure in the center
of the rear edge of the fuel door and it will
pop open.
To remove the fuel cap, turn it slowly to the left
(counterclockwise). The fuel cap has a spring in it;
if the cap is released too soon, it will spring
back to the right.
While refueling, hang the tethered fuel cap from
the hook on the fuel door.
432

{CAUTION:
If you spill fuel and then something
ignites it, you could be badly burned. Fuel
can spray out on you if you open the fuel
cap too quickly. This spray can happen if
your tank is nearly full, and is more likely
in hot weather. Open the fuel cap slowly
and wait for any hiss noise to stop. Then
unscrew the cap all the way.
Be careful not to spill fuel. Do not top off or overll
the tank and wait a few seconds after you have
nished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon
as possible. SeeWashing Your Vehicle on
page 532.
When replacing the fuel cap, turn it to the right
(clockwise) until it clicks. Make sure the cap is fully
installed. The diagnostic system can determine
if the fuel cap has been left off or improperly
installed. This would allow fuel to evaporate into
the atmosphere. SeeMalfunction Indicator
Lamp on page 236.If your vehicle has a Driver Information Center
(DIC), the TIGHTEN GAS CAP message will be
displayed if the fuel cap is not properly installed.
{CAUTION:
If a re starts while you are refueling, do
not remove the nozzle. Shut off the ow of
fuel by shutting off the pump or by
notifying the station attendant. Leave the
area immediately.
Notice:If you need a new fuel cap, be sure to
get the right type. Your dealer can get one
for you. If you get the wrong type, it may not
t properly. This may cause your malfunction
indicator lamp to light and may damage
your fuel tank and emissions system. See
Malfunction Indicator Lamp on page 236.
433

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it
is in your vehicle. Static electricity
discharge from the container can ignite the
gasoline vapor. You can be badly burned
and your vehicle damaged if this occurs.
To help avoid injury to you and others:
Dispense gasoline only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup
bed, or on any surface other than the
ground.
Bring the ll nozzle in contact with the
inside of the ll opening before
operating the nozzle. Contact should
be maintained until the lling is
complete.
Do not smoke while pumping gasoline.
Checking Things Under
the Hood
{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.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
434

Engine Oil
If the CHECK OIL LEVEL message appears on
the instrument cluster, it means you need to check
your engine oil level right away.
For more information, see CHECK OIL LEVEL
underDIC Warnings and Messages on page 254.
You should check your engine oil level regularly;
this is an added reminder.
Checking Engine Oil
It is a good idea to check your engine oil every
time you get fuel. In order to get an accurate
reading, the oil must be warm and the vehicle must
be on level ground.The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 436
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
438

5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shutoff and
the coolant is cold. If necessary, repeat
coolant ll procedure steps 1 through 6.
Engine Fan Noise
If your 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 you
may hear an increase in fan noise. 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.You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during
most everyday driving. The fans may turn off if no
cooling is required. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, or
if you are operating your air conditioning system,
the fans may change to high speed and you
may hear an increase in fan noise. 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.
460

What to Use
Refer to the Maintenance Schedule to determine
what kind of lubricant to use. SeeRecommended
Fluids and Lubricants on page 564.
Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been
preset at the factory and should need no further
adjustment.
However, if the vehicle is damaged in an accident,
the aim of the headlamps may be affected and
adjustment may be necessary.
If oncoming vehicles ash their high beams at
you, this may mean the vertical aim of your
headlamps needs to be adjusted.
It is recommended that the vehicle is taken to your
dealer for service if the headlamps need to be
adjusted. It is possible however, to re-aim
the headlamps as described in the following
procedure.The vehicle should be properly prepared as
follows:
The vehicle should be placed so the
headlamps are 25 ft. (7.6 m) from a light
colored wall.
The vehicle must have all four tires on a level
surface which is level all the way to the wall.
The vehicle should be placed so it is
perpendicular to the wall.
The vehicle should not have any snow, ice, or
mud on it.
The vehicle should be fully assembled and all
other work stopped while headlamp aiming is
being performed.
The vehicle should be normally loaded with
a full tank of fuel and one person or
160 lbs (75 kg) sitting on the driver’s seat.
Tires should be properly inated.
The spare tire is in its proper location in the
vehicle.
Headlamp aiming is done with the vehicle’s
low-beam headlamps. The high-beam headlamps
will be correctly aimed if the low-beam headlamps
are aimed properly.
475