2007 GMC SIERRA engine

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 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.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 the fuel system and also damage
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 dealer for service.
490

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identication Number
(VIN) shows the code letter or number that
identies your vehicle’s engine. The VIN is at the
top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 607.
If your vehicle has the 5.3L V8 engine (VIN
Code 0) or the 5.3L V8 engine (VIN Code 3), you
can use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E85);
also seeFuel on page 488. In all other engines,
use only the unleaded gasoline described
underGasoline Octane on page 489.
Only vehicles that have the 5.3L V8 engine
(VIN Code 0) or the 5.3L V8 engine (VIN Code 3)
can use 85% ethanol fuel (E85). We encourage
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 (www.eere.energy.gov/afdc/infrastructure/
locator.html) that can help you nd E85 fuel.
Those stations that do have E85 should have a
label indicating ethanol content. Do not use
the fuel if the ethanol content is greater than 85%.
At a minimum, E85 should meet ASTM
Specication D 5798. By denition, this means
that fuel labeled E85 will have an ethanol content
between 70% and 85%. Filling the fuel tank
with fuel mixtures that do not meet ASTM
specications can affect driveability and could
cause the malfunction indicator lamp to come on.
491

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.
493

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.
496

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:
498

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter (Gasoline Engines) on page 505.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter (Gasoline
Engines) on page 505.
C. Coolant Surge Tank and Pressure Cap. See
Cooling System on page 520andCoolant
Surge Tank Pressure Cap on page 516.
D. Positive (+) Terminal. SeeJump Starting on
page 532.
E. Battery. SeeBattery on page 531.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 500.
G. Automatic Transmission Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 508.H. Remote Negative (−) Terminal (Out of View).
SeeJump Starting on page 532.
I. Engine Oil Dipstick (Out of View). See
“Checking Engine Oil” underEngine Oil
(Gasoline Engine) on page 500.
J. Engine Cooling Fan. SeeCooling System on
page 520.
K. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 526.
L. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 528.
M. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 612.
N. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 527.
499

Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine
Oil” in the DURAMAX®Diesel Engine Supplement.
If the CHECK OIL LEVEL light appears on the
instrument cluster, except vehicles that have the
4.3L engine, check the engine oil level right away.
For more information, seeDriver Information
Center (DIC) on page 267. You should check the
engine oil level regularly; this is an added
reminder.
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.
SeeEngine Compartment Overview on page 498
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.
500

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, you need to add at least one
quart/liter of oil. But you must use the right kind.
This section explains what kind of oil to use.
For engine oil crankcase capacity, seeCapacities
and Specications on page 616.
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 498for 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.
501