2005 CHEVROLET SILVERADO check engine

Gasoline Octane
For all except vehicles with the 6.0L 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 6.0L 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.
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 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 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.
5-6

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

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 5-38.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine 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. Engine Cooling Fan. SeeCooling 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 5-52.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-52.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-127.
N. Battery. SeeBattery on page 5-51.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-47.
5-15

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 5-38.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine 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. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
G. Engine Cooling Fan. SeeCooling System on
page 5-40.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-52.
I. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-46.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-52.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-127.
N. Battery. SeeBattery on page 5-51.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-47.
5-17

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 5-38.
C. Air Filter Restriction Indicator (If Equipped).
SeeEngine 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. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-20.
G. Engine Cooling Fan. SeeCooling System on
page 5-40.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-52.
I. Remote Positive (+) Terminal. SeeJump Starting on
page 5-52.
J. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-46.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-48.
L. Clutch Fluid Reservoir (If Equipped). SeeHydraulic
Clutch on page 5-34.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-127.
N. Battery. SeeBattery on page 5-51.
O. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-47.
5-19

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 equipped with the
4.3L engine), it means you need to check your engine oil
level right away.
For more information, seeDriver Information Center
(DIC) on page 3-50.
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 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.
5-20

If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
Engine Oil Life System
(Gasoline Engine)
When to Change Engine Oil
Your vehicle has a computer system that lets you know
when to change the engine oil and lter. This is based on
engine revolutions and engine temperature, and not on
mileage. Based on driving conditions, the mileage atwhich an oil change will be indicated can vary
considerably. For the oil life system to work properly,
you must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. SeeDIC Warnings and Messages on
page 3-54. Change your oil as soon as possible within
the next 600 miles (1 000 km). It is possible that,
if you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil and lter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system.
It is also important to check your oil regularly and keep
it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
5-23

6. Reinstall the cover and tighten the screws.
7. Reset the air lter restriction indicator, if equipped,
by pressing the top button on the indicator.
{CAUTION:
Operating the engine with the air cleaner/lter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there
and the engine backres, you could be burned.
Do not drive with it off, and be careful working
on the engine with the air cleaner/lter off.
Automatic Transmission Fluid
(Except Allison Transmission
®)
When to Check and Change
Automatic Transmission Fluid
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services (Gasoline Engine) on
page 6-7, and be sure to use the transmission uid
listed inRecommended Fluids and Lubricants
(Gasoline Engine) on page 6-14.
How to Check Automatic
Transmission Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
5-27