2003 CHEVROLET C/K oil

6-6 What Fuel to Use
In the United States, for best results use Number 2-D
diesel fuel year
-round (above and below freezing
conditions) as oil companies blend Number 2
-D fuel to
address climate differences. Number 1
-D diesel fuel
may be used in very cold temperatures (when it stays
below 0
F or
-18
C); however, it will produce a power
and fuel economy loss. Avoid the use of Number 1
-D
diesel fuel in warm or hot climates. It may result in
stalling, poor starting when the engine is hot and may
damage the fuel injection system.
At a minimum, the diesel fuel you use should meet
specifications ASTM D975
-00 (Grade Low Sulfur) in
the United States. In addition, the Engine Manufacturers
Association (EMA) has identified properties of an
improved diesel fuel for better engine performance and
durability. Diesel fuels corresponding to the EMA
Recommended Guideline on Premium Diesel Fuel
(FQP
-1A) could provide better starting, less noise and
better vehicle performance. If there are questions about
the fuel you are using, contact your fuel supplier.Diesel fuel may foam when you fill your tank. This can
cause the automatic pump nozzle to shut off, even
though your tank isn't full. If this happens, just wait for
the foaming to stop and then continue to fill your tank.
CAUTION:
Heat coming from the engine may cause the fuel
to expand and force the fuel out of your tank. If
something ignites the fuel, a fire could start and
people could be burned. To help avoid this, fill
your fuel tank only until the automatic nozzle
shuts off. Don't try to ªtop it off.º

6-7
What Fuel to Use in Canada
Canadian fuels are blended for seasonal changes. Diesel
Type ªAº fuel is blended for better cold weather starting
(below 0
F or
-18
C); however, you may notice some
power and fuel economy loss. If Type ªAº fuel is used
in warmer temperatures, stalling and hard starting may
occur. Diesel Type ªBº fuel is blended for temperatures
above 0
F (
-18
C). The emission control system
requires the use of diesel fuel with low
-sulfur (.05% by
weight) content. Both low
- and higher-sulfur fuels will
be available in Canada. Only low
-sulfur diesel fuels are
available in the United States. It is important that
diesel
-powered trucks are refueled only with low-sulfur
fuel. Use of fuels with higher
-sulfur content will affect
the function of the emission components and may
cause reduced performance, excessive smoke and
unpleasant odor.
At a minimum, the diesel fuel you use should meet
specifications CAN/CGSB
-3.517-2000 (Low Sulfur
Diesel) in Canada. In addition, the Engine
Manufacturers Association (EMA) has identified
properties of an improved diesel fuel for better engine
performance and durability (FQP
-1A). Diesel fuels
corresponding to the EMA description could provide
better starting, less noise and better vehicle
performance. If there are questions about the fuel you
are using, contact your fuel supplier.
Very Cold Weather Operation
Follow the instructions listed previously under the
heading ªWhat Fuel to Use.º
NOTICE:
Never use home heating oil or gasoline in your
diesel engine. They can cause engine damage.
In cold weather, your fuel filter may become clogged
(waxed). To unclog it, move the vehicle to a warm
garage area and warm the filter to between 32
F and
50
F (0
C to 10
C). You won't need to replace it.
Additional information on the fuel filter follows.

6-10
To drain water, do the following:
1. Stop and park the vehicle in a safe place. Turn off
the engine and apply the parking brake.
2. Remove the fuel cap.
3. Place a fuel
-resistant container under the fuel filter.
The filter drain valve is located on the bottom of the
fuel filter. The fuel filter is located in the engine
compartment on the passenger's side of the vehicle,
or on the driver's side frame rail near the engine.
4. Open the drain valve by
turning two to three
turns. When fuel
empties from the valve,
all the water has been
drained. Close the valve
hand tight.5. Remove the fuel
-resistant container and properly
dispose of the contaminated fuel. To find out how to
properly dispose of contaminated diesel fuel, see
ªWhat to Do with Used Oilº in the ªEngine Oil
(Diesel Engines)º part, later in this section.
6. Install the fuel cap.
7. Start the engine and let it run for a few minutes.
If the engine stalls, the fuel system may need to be
primed. While draining the water from the fuel filter,
air may enter the fuel system. If air has entered the
fuel system the fuel system will need to be primed.
Refer to ªFuel Primingº later in this section.
If the water in fuel indicator comes on again after
driving a short distance or the engine runs rough or
stalls, a large amount of water has probably been
pumped into the fuel tank. The fuel tank should
be purged.
Fuel Priming
In order for the DURAMAX diesel engine fuel system
to work properly, the fuel lines must be full of fuel and
contain no air. If air gets into the fuel lines, it will be
necessary to prime the fuel lines to eliminate air before
operating the vehicle.

6-15
Fuels in Foreign Countries
(Gasoline Engines)
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard to
find. Never use leaded gasoline or any other fuel not
recommended in the previous text on fuel. Costly repairs
caused by use of improper fuel wouldn't be covered by
your warranty.
To check on fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you'll be driving.
Filling Your Tank
C4/C5 Models

6-18
Checking Things Under the Hood
CAUTION:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, 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 Latches
To tilt the hood forward, pull back and up on each of the
hood latches, located above the wheel wells on both
sides of the vehicle.

6-21
Among those acts presumed to constitute tampering are
the acts listed below.
Insulation:

Removal of the noise shields or any underhood
insulation.
Engine:

Removal or rendering engine speed governor
(if equipped) inoperative so as to allow engine
speed to exceed manufacturer specifications.
Fan and Drive:

Removal of fan clutch (if equipped) or rendering
clutch inoperative.

Removal of the fan shroud (if equipped).
Air Intake:

Removal of the air cleaner silencer.

Modification of the air cleaner.
Exhaust:

Removal of the muffler and/or resonator.

Removal of the exhaust pipes and exhaust
pipe clamps.Engine Oil (Gasoline Engine)
If the low oil light appears
on the instrument cluster, it
means you need to check
your engine oil level right
away. For more
information, see ªLow Oil
Lightº in the Index.
You should check your engine oil level regularly; this is
an added reminder.

6-22 Checking Engine Oil
It's 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
is located in the engine
compartment on the
driver's side of the vehicle.
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.

6-23 When to Add Engine Oil
If the oil is at or below the cross-hatched area, then
you'll need to add at least one quart of oil. But you must
use the right kind. This part explains what kind of oil to
use. For engine oil crankcase capacity, see ªCapacities
and Specificationsº in the Index.
NOTICE:
Don't add too much oil. If your engine has
so much oil that the oil level gets above the
cross
-hatched area upper mark that shows
the proper operating range, your engine could
be damaged.
The engine oil fill cap is
located near the engine oil
dipstick in the engine
compartment, on the
driver's side of the vehicle.
Be sure to fill it enough to put the level somewhere in
the proper operating range. Push the dipstick all the way
back in when you're through.