2005 GMC SIERRA engine

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
If your vehicle has a diesel engine, see “Diesel Fuel
Requirements and Fuel System” in the Diesel Engine
Supplement.
For vehicles with gasoline engines, please read this.
Gasoline Octane
For all except vehicles with the 6000 V8 (VIN Code N)
engine, use regular unleaded gasoline with a posted
octane of 87 or higher. If the octane is less than 87, you
may get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you might damage your
engine. A little pinging noise when you accelerate or drive
uphill is considered normal. This does not indicate a
problem exists or that a higher-octane fuel is necessary.
If you are using 87 octane or higher-octane fuel and hear
heavy knocking, your engine needs service.
If you have the 6000 V8 (VIN Code N) engine, use
premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also
use middle grade or regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration
may be slightly reduced. If the octane is less than 87,
you may get a heavy knocking noise when you drive.
If this occurs, use gasoline rated at 87 octane or higher
as soon as possible. Otherwise, you might damage
your engine.
5-6

Gasoline Specications
It is recommended that gasoline meet specications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of
Automobile Manufacturers at
www.autoalliance.org/fuel_charter.htm. Gasoline
meeting these specications could provide improved
driveability and emission control system performance
compared to other gasoline.
California Fuel
If your vehicle is certied to meet California Emission
Standards (see the underhood emission control label),
it is designed to operate on fuels that meet California
specications. 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 3-44.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.
General Motors recommends that you buy gasolines
that are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems
due to dirty injectors or valves, try a different brand of
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 to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specications described earlier.
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.
5-7

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 does
not recommend 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 E-85 (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 5-120.If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E-85);
also seeFuel on page 5-6. In all other engines, including
the 5.3L V8 (VIN Code T), use only regular unleaded
gasoline.
Only vehicles that have the 5.3L V8 engine (VIN Code Z)
may use 85% ethanol fuel (E-85). General Motors
encourages the use of E-85 in vehicles that are designed
to use it. The ethanol in E-85 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
(E-85) pump available. The U. S. Department of
Energy has an alternative fuels website
(http://www.afdc.doe.gov/refueling_mapsite.shtml) that
can help you nd E-85 fuel. Those stations that do have
E-85 should have a label indicating ethanol content.
Do not use the fuel if the ethanol content isgreaterthan
85%. Your vehicle may not operate properly if the
ethanol content is greater than 85%.
5-8

Filling Your 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 remove the fuel cap, turn it slowly to the left
(counterclockwise). It will require more effort to turn the
fuel cap on the last turn as you loosen it.
{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.
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.
5-10

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.
5-12

Engine Compartment Overview
When you open the hood on the VORTEC™ 4300 V6 engine, here is what you will see:
5-14

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-25.
B. Coolant Surge Tank and Pressure Cap. SeeEngine
Coolant on page 5-35andCoolant Surge Tank
Pressure Cap on page 5-37.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-25.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
E. Automatic Transmission Fluid Dipstick (If Equipped).
See “Checking the Fluid Level” underAutomatic
Transmission Fluid (Except Allison Transmission
®)
on page 5-27orAutomatic Transmission Fluid
(Allison Transmission
®) on page 5-30.
F. Electric Engine Cooling Fan (If Equipped). See
Cooling System on page 5-40.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-46.
I. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-53.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-53.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-49.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-125.
N. Battery. SeeBattery on page 5-52.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-48.
5-15

When you open the hood on the VORTEC™ 5300 V8 engine (VORTEC™ 4800 and 6000 V8 engines similar),
here is what you will see:
5-16