2008 GMC SIERRA Owner's Manual

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 could be because the E85 fuel is not
properly formulated for your climate. If this happens,
switching to gasoline or adding gasoline to the fuel tank
can 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
three gallons (11 L) when refueling. You should drive the
vehicle immediately after refueling for at least seven
miles (11 km) to allow the vehicle to adapt to the change
in ethanol concentration.
E85 has less energy per gallon than gasoline, so you
will need to rell the fuel tank more often when using
E85 than when you are using gasoline. SeeFilling the
Tank on page 5-10.Notice:Some additives are not compatible with
E85 fuel and can harm your vehicle’s fuel system.
Do not add anything to E85. Damage caused by
additives would not be covered by your new vehicle
warranty.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage 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 might 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.
5-9

Filling the Tank
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
{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.
Do not use cellular phones. 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. Do not re-enter the vehicle
while pumping fuel. 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. If the vehicle has
E85 fuel capability, a yellow cap with the words
“E85 / Gasoline” can be seen.
5-10

To remove the fuel cap, turn it slowly counterclockwise.
{CAUTION:
Fuel can spray out on you if you open the fuel
cap too quickly. If you spill fuel and then
something ignites it, you could be badly
burned. 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.
If your vehicle is a dual fuel tank chassis cab model,
and it runs out of fuel, refuel the front fuel tank rst to
ensure a quick restart.
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. See
Washing Your Vehicle on page 5-116.
When replacing the fuel cap, turn it clockwise until it
clicks. It will require more effort to turn the fuel cap on
the last turn as you tighten it. Make sure the cap is
fully installed. The diagnostic system can determine ifthe fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the atmosphere.
SeeMalfunction Indicator Lamp on page 3-48.
The TIGHTEN GAS CAP message will be displayed on
the Driver Information Center (DIC) if the fuel cap is
not properly installed. SeeDIC Warnings and Messages
on page 3-63for more information.
{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/retailer 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. SeeMalfunction Indicator Lamp
on page 3-48.
5-11

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 fuel vapor. You
can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
Dispense fuel 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 fuel.
Do not use a cellular phone while
pumping fuel.
Checking Things Under the
Hood
{CAUTION:
An electric engine cooling fan can start even
when the engine is not running. To avoid
injury, always keep hands, clothing, and tools
away from any engine cooling 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.
5-12

Hood Release
To open the hood do the following:
1. Pull the handle with
this symbol on it. It is
located inside the
vehicle to the left of the
brake pedal.
2. Then go to the front of the vehicle and locate the
secondary hood release. This is located under the
hood, near the center of the grille.
3. Push the secondary hood release to the right.
4. Lift the hood.
Before closing the hood, be sure all the ller caps
are on properly. Then bring the hood from full open
to within 6 inches (152 mm) from the closed
position, pause, then push the front center of the
hood with a swift, rm motion to fully close the hood.
5-13

Engine Compartment Overview
If your vehicle has the DURAMAX®Diesel engine, see the DURAMAX®Diesel manual for more information.
When you open the hood on the 5.3L engine (4.3L, 4.8L and 6.0L similar), this is what you will see:
5-14

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 5-19.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline Engines)
on page 5-19.
C. Coolant Surge Tank and Pressure Cap. SeeCooling
System on page 5-34andCoolant Surge Tank
Pressure Cap on page 5-30.
D. Positive (+) Terminal. SeeJump Starting
on page 5-46.
E. Battery. SeeBattery on page 5-45.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-15.
G. Automatic Transmission Dipstick. See “Checking the
Fluid Level” underAutomatic Transmission Fluid
(6-Speed Transmission) on page 5-22orAutomatic
Transmission Fluid (4-Speed Transmission)
on page 5-25.
H. Remote Negative (−) Terminal (Out of View). See
Jump Starting on page 5-46.
I. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil (Gasoline Engine)
on page 5-15.
J. Engine Cooling Fan. SeeCooling System
on page 5-34.
K. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-39.L. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-42.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-126.
N. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-40.
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine Oil” in
the DURAMAX®Diesel manual.
Checking Engine Oil
It is a good idea to check the 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. See
Engine Compartment Overview on page 5-14for
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.
5-15

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip of
the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind of oil
to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 5-130.
Notice:Do not add too much oil. If the engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.SeeEngine Compartment
Overview on page 5-14for
the location of the engine
oil ll cap.
Be sure to add enough oil to put the level somewhere in
the proper operating range. Push the dipstick all the
way back in when you are through.
5-16