engine CHEVROLET EXPRESS 2004 Workshop Manual

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. See
Malfunction Indicator Lamp on page 3-32. 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.
5-6

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).
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
5-8

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:
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.
5-10

Engine Compartment Overview
When you lift the hood, here is what you will see:
5-12

A. Battery. SeeBattery on page 5-37.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-24.
C. Coolant Recovery Tank. SeeCooling System on
page 5-26.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-19.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-13.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-17.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-32.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-34.
J. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-33.Engine Oil
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. See
Engine Compartment Overview on page 5-12for
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.
5-13

When to Add Engine Oil
If the oil is at or below the cross-hatched area at the tip
of the dipstick, then you will need to add at least one
quart 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 5-97.
Notice:Do not add too much oil. If your engine has
so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, your engine could be damaged.SeeEngine Compartment
Overview on page 5-12for
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.
What Kind of Engine Oil to Use
Look for two things:
GM6094M
Your vehicle’s engine requires oil meeting GM
Standard GM6094M. You should look for and use
only an oil that meets GM Standard GM6094M.
5-14

SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle.
These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.
Oils meeting these
requirements should also
have the starburst
symbol on the container.
This symbol indicates
that the oil has been
certied by the American
Petroleum Institute (API).
You should look for this information on the oil container,
and useonlythose oils that are identied as meeting
GM Standard GM6094M and have the starburst symbol
on the front of the oil container.
Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
5-15

GM Goodwrench®oil meets all the requirements for
your vehicle.
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
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 at which 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 light will come on. See
Change Engine Oil Light on page 3-35. 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.
How to Reset the Engine Oil
Life System
The Engine Oil Life System calculates when to change
your engine oil and lter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change your oil prior to a change engine oil
light being turned on, reset the system.
5-16

To reset the change engine oil light, do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds.
3. If the Change Engine Oil light ashes for
ve seconds, the system is reset.
4. Turn the key to LOCK.
If the change engine oil light comes back on when you
start your vehicle, the engine oil life system has not
reset. Repeat the procedure. If it still does not reset, see
your dealer for service. SeeChange Engine Oil Light
on page 3-35.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it inthe trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by taking it
to a place that collects used oil. If you have a problem
properly disposing of your used oil, ask your dealer, a
service station or a local recycling center for help.
Engine Air Cleaner/Filter
The engine air cleaner/lter is located near the center of
the engine compartment. SeeEngine Compartment
Overview on page 5-12for more information on location.
5-17

When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace at the rst oil change after
50,000 miles (83 000 km). SeeScheduled Maintenance
on page 6-4for more information. If you are driving
in dusty/dirty conditions, inspect the lter at each engine
oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/lter, remove the lter from
the vehicle and lightly shake the lter to release
loose dust and dirt. If the lter remains caked with dirt, a
new lter is required.
To inspect or replace the engine air cleaner/lter, do the
following:
1. Unhook the retainer clips and remove the cover.
2. Lift the lter out of the engine air cleaner/lter
housing. Care should be taken to dislodge as
little dirt as possible.3. Clean the engine air cleaner/lter housing.
4. Inspect or replace the engine air cleaner/lter. Make
sure that the lter ts properly into the housing.
5. Reinstall the cover and fasten the retaining clips.
{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 ame 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.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/lter in place when you
are driving.
5-18