2004 CHEVROLET EXPRESS CARGO VAN fuel

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.
Hood Release
To open the hood, do the following:
1. Pull this handle inside
the vehicle. It is located
in front of the driver’s
side door frame
near the oor.
5-10

A. Battery. SeeBattery on page 5-42.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-25.
C. Coolant Recovery Tank. SeeCooling System on
page 5-28.
D. Transmission Fluid Dipstick. SeeAutomatic
Transmission Fluid on page 5-19.
E. Engine Oil Fill. SeeEngine Oil on page 5-13.
F. Engine Oil Dipstick. SeeEngine Oil on page 5-13.
G. Air Filter Restriction Indicator. SeeEngine Air
Cleaner/Filter on page 5-18.
H. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.
I. Power Steering Reservoir. SeePower Steering Fluid
on page 5-36.
J. Brake Master Cylinder. SeeBrakes on page 5-39.
K. Windshield Washer Fluid. SeeWindshield Washer
Fluid on page 5-38.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.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.
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

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.
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.
When to Change Engine Oil (GM Oil
Life System)
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.
Change your oil as soon as possible within the next two
times you stop for fuel. 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.
5-16

Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages. So
you may hear an increase in fan noise. This is
normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down
when additional cooling is not required and the clutch
partially disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
Power Steering Fluid
The power steering uid reservoir is located in the
engine compartment on the driver’s side of the vehicle.
SeeEngine Compartment Overview on page 5-12
for more information on location.
5-36

Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to its
width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.
Cold Ination Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeInation - Tire Pressure on page 5-66.Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the U.S.
Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identication
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-33.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-33.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-33.
Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
There are 6.9 kPa’s to one psi.
5-64

Treadwear Indicators:Narrow bands, sometimes
called “wear bars,” that show across the tread of a tire
when only 2/32 inch of tread remains. SeeWhen It
Is Time for New Tires on page 5-69.
UTQGS:Uniform Tire Quality Grading Standards, a tire
information system that provides consumers with
ratings for a tire’s traction, temperature and treadwear.
Ratings are determined by tire manufacturers using
government testing procedures. The ratings are molded
into the sidewall of the tire. SeeUniform Tire Quality
Grading on page 5-71.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs. (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-33.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight and cargo weight.
Vehicle Placard:A label permanently attached to a
vehicle showing the original equipment tire size
and recommended ination pressure. SeeLoading Your
Vehicle on page 4-33.Ination - Tire Pressure
The tire and loading information label, shows the correct
ination pressures for your tires when they’re cold.
“Cold” means your vehicle has been sitting for at least
three hours or driven no more than 1 mile (1.6 km). See
Loading Your Vehicle on page 4-33, for the location
of your vehicle’s tire and loading information label.
Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), you can get
the following:
Too much exing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overination), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
5-66

Sheet Metal Damage
If your vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti-corrosion material to parts repaired or
replaced to restore corrosion protection.
Original manufacturer replacement parts will provide the
corrosion protection while maintaining the warranty.
Finish Damage
Any stone chips, fractures or deep scratches in the
nish should be repaired right away. Bare metal
will corrode quickly and may develop into major repair
expense.
Minor chips and scratches can be repaired with touch-up
materials avaliable from your dealer. Larger areas of
nish damage can be corrected in your dealer’s
body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, oor pan and
exhaust system even though they have corrosion
protection.At least every spring, ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being ushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage
can take two forms: blotchy, ring-shaped discolorations,
and small, irregular dark spots etched into the paint
surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs rst.
5-98

Fuse Usage
6 Ignition 0
7 Stop Lamp
8 Right Rear Defogger/Heated Mirror
9Right Daytime Running Lamp/Turn
Signal
10Left Daytime Running Lamp/Turn
Signal
11 Truck Body Control Module 4
12 Fuel Pump
13 Trailer
14 Flasher
15 Horn
16 Truck Body Control Module 3
17 Trailer Stop/Turn Signal
18 Truck Body Control Module 2
19 Truck Body Control Module
20 Remote Function Actuator
21 Engine 2Fuse Usage
22 Ignition E
23 Engine 1
24 Truck Body Control Module Ignition 1
25 Spare
26 RPA/Inside Rearview Mirror
27 Crankcase
28Brake Transmission Shift Interlock
System
29 Auxiliary Power Outlets
30 Cigarette Lighter
31 Instrument Panel Cluster
32 Air Conditioning
33 Spare
34 Vent
35 Spare
36 Vehicle Back Up
37Supplemental Inatable Restraint
System
5-104