2003 CHEVROLET C/K engine oil

2-19
Starting the Diesel Engine
If you have a Caterpillar diesel engine, also refer to your
Caterpillar
Diesel Engine Operation & Maintenance
Manual for starting procedure.
For vehicles with the DURAMAX diesel engine, also
see ªStarting Your DURAMAX Diesel Engineº
following.
To make starting easier in cold weather (below 32F or
0C), the proper viscosity engine oil should be used.
See ªEngine Oilº in the Index. It's also best to heat the
engine oil first. You can do this by using an engine
coolant heater.
NOTICE:
If you ever need to have your vehicle towed, see
the part of this manual that tells how to do it
without damaging your vehicle. See ªTowing
Your Vehicleº in the Index.
Restarting the Diesel Engine While Moving
(Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you'll first have to shift the automatic
transmission to NEUTRAL (N). This safety feature
prevents starting the engine when the transmission is
in a drive gear.
Stopping the Diesel Engine
If you have a Caterpillar diesel engine, see your
Caterpillar
Diesel Engine Operation &
Maintenance Manual.
1. Set the parking brake and shift to NEUTRAL (N)
or PARK (P).
2. Turn the ignition key to OFF.
If your vehicle has a two
-speed axle, see ªRear Axle,
Tw o
-Speed Electric Shift Controlº or ªRear Axle,
Tw o
-Speed Airshift Controlº in the Index.

2-20 Cold Weather Starting
(Caterpillar

Diesel)
Because the diesel engine uses compression ignition, it
is harder to start in cold weather than a gasoline engine.
The air intake heater and use of the proper engine oil,
optional engine coolant heaters and optional ether
injection systems help cold weather starting. See the
Caterpillar

Diesel Engine Operation & Maintenance
Manual for more information.
NOTICE:
Your diesel engine has an electric air intake
heater system which reduces white smoke and
helps start the engine in cold weather. Do not
spray starting fluid into the air intake where it
can contact the heater elements.
If you don't have the GM Automatic Ether
Injection System, don't use starting fluid or you
could damage your engine. If you have the GM
system, use only GM approved starting fluid that
has been tested to establish compatibility with the
air inlet heater system.
Diesel Engine Warm-Up
Several factors affect how quickly your diesel engine
warms up. These can include outside temperature,
engine load, idle time and your vehicle's option content.
Your vehicle may be equipped with some features that
can help the engine reach operating temperature sooner.
Some of these features are discussed below.
Also, remember that an automatic transmission adds
heat to the cooling system through the heat exchanger in
the radiator. Because of this, vehicles equipped with
automatic transmissions are often able to retain engine
coolant heat better than manual transmission vehicles.
See your Caterpillar

Operation & Maintenance manual
for additional diesel engine warm
-up information.

2-21 Engine Alarm and Automatic Shutdown
(If Equipped)
Your check gages light will come on if the system senses
high engine temperature or low engine oil pressure. If high
engine temperature or low engine oil pressure is detected,
you will also hear a tone alarm at two beats per second.
The alarm and the light will remain on until the condition
is fixed. If the engine temperature or oil pressure condition
worsens, the tone alarm will go to five beats per second.
If the system senses low engine coolant, the five beat
per second alarm and the low coolant warning light will
come on.
The five beats per second tone alarm means that your
engine will shut down in approximately 25
-30 seconds.
There is also an engine shutdown light to indicate that
the engine will shut down. See ªAutomatic Engine
Shutdown Lightº later in this section.
Pull off the road and shut off the engine. Don't start it
until the reason for the problem is known, and the
problem is fixed. If the engine shuts down when you are
still in traffic, you can restart the engine and get another
25
-30 seconds of operation. Do this only if you have to,
since there is a problem that can harm the engine if it
isn't fixed. Engine automatic shutdown, for gasoline
engines, requires activation by your dealer.
High Idle System (Caterpillar
Diesel
and Gasoline Engines)
Your vehicle has both automatic and manual high idle
capabilities.
Automatic High Idle System (Diesel Engines)
(If Equipped)
The automatic high idle feature will engage whenever
you start your vehicle and the engine is below the preset
operating temperature. This will help decrease engine
warm
-up time.
Idle speed will then return to normal under any of the
following conditions:

The engine reaches the preset operating temperature
or has been operating for at least ten minutes.

The brake pedal is pressed.

The manual transmission clutch pedal is pressed or,
the automatic transmission (if equipped) is shifted
from NEUTRAL (N) or PARK (P).

The vehicle speed exceeds approximately
5 mph (8 km/h).

The throttle is pressed.

2-25
NOTICE:
If the wait to start light stays on, it means that
your vehicle could have one of several problems,
so you should have it serviced right away.
3. If the engine does not start after 15 seconds of
cranking, turn the ignition key to OFF. Wait
one minute for the starter to cool, then try the
same steps again.
If you're trying to start your engine after you've run
out of fuel, follow the steps in ªRunning Out of Fuel.º
See ªDiesel Fuel Requirements and Fuel Systemº in
the Index.
When your engine is cold, let it run for a few minutes
before you move your vehicle. This lets oil pressure
build up. Your engine will sound louder when it's cold.
NOTICE:
If you're not in an idling vehicle and the engine
overheats, you wouldn't be there to see the
overheated engine condition. This could damage
your vehicle. Don't let your engine run when
you're not in your vehicle.
Cold Weather Starting (Diesel Engine)
The following tips will help you get good starting in
cold weather.
Use the recommended engine oil when the outside
temperature drops below freezing. See ªEngine Oilº in
the Index. When the outside temperature drops below
0
F (
-18
C), use of the engine coolant heater is
recommended.
If you experience longer cranking times, notice an
unusual amount of exhaust smoke or are at higher
altitudes (over 7,000 ft. or 2 135 m), you may use your
engine coolant heater. See ªEngine Coolant Heaterº in
the Index.
See ªDiesel Fuel Requirements and Fuel Systemº in the
Index for information on what fuel to use in cold weather.

2-26 If Your Diesel Engine Won't Start
If you've run out of fuel, look at ªRunning Out of Fuel.º
See ªDiesel Fuel Requirements and Fuel Systemº in
the Index.
If you're not out of fuel, and your engine won't start,
do this:
Turn your ignition key to RUN. IMMEDIATELY
after the wait to start light goes off, turn the ignition
key to START.
If the light doesn't go off, wait a few seconds, then try
starting your engine again. And, see your dealer as soon
as you can for a starting system check.
If the light comes on and then goes off and you know
your batteries are charged, but your engine still won't
start, your vehicle needs service.
If the light does not come on when the engine is cold,
your vehicle needs service.If your batteries don't have enough charge to start your
engine, see ªBatteryº in the owner's manual.
Be sure you have the right oil for your engine, and that
you've changed the oil at the proper times. If you use
the wrong oil, your engine may be harder to start.
Be sure you are using the proper fuel for existing
weather conditions. See ªDiesel Fuel Requirements and
Fuel Systemº in the Index.
If the engine starts, runs a short time, then stops, your
vehicle needs service.
CAUTION:
Do not use gasoline or starting ªaids,º such as
ether, in the air intake. They could damage your
engine. There could also be a fire, which could
cause serious personal injury.

2-27
Engine Checks Before Operating
When you've started your engine, let it run for 20 to
30 seconds before you put a load on the engine. But
don't leave the vehicle while the engine is running.
Avoid unnecessary idling of diesel engine equipped
vehicles.
If the engine idles too long, the temperature of the
engine coolant will fall below the normal operating
range. Low engine operating temperature causes several
conditions which affect engine operation and reduce
engine life.
The engine should be permitted to go through a
warm
-up period. Operate the vehicle at a minimum of
600 rpm during the warm
-up period. During this period
and during operation, the following observations should
be made.
During this warm
-up period, check your warning lights
and gages:

If oil pressure doesn't begin to rise within
15 seconds of starting, stop the engine and
find the cause.
If the engine coolant temperature gage needle goes
into the hot area on the gage, stop the engine and
find the cause of the overheating.

If you have air brakes, the dual
-needle air pressure
gage should read at least 115 psi (790 kPa) for both
service systems before you try to move the vehicle.
When air pressure is below 60 psi (420 kPa), the
LOW AIR light will come on and you will hear a
tone alarm. If the pressure doesn't build up or
drops during warm
-up, stop the engine and find
the cause before you try to move the vehicle.
Recommended air pressure before actually driving
away is 120 psi (830 kPa).

The charging system light should come on when
the ignition key is turned to RUN or START and
should go out when the engine is running above idle.
If the light doesn't go out or comes back on during
normal engine operation, have the charging system
checked right away. (This light tells you if the
generator is not charging; it doesn't reflect the
condition of the battery.)

2-87 Oil Pressure Gage
United States Canada
The engine oil pressure gage, on the lower right portion
of your instrument panel cluster, shows engine oil
pressure in psi (pounds per square inch) or in kPa
(kilopascals). Oil pressure may vary with outside
temperature and oil viscosity, but readings of 30 to
40 psi (205 to 275 kPa) on gasoline engines at operating
temperature and moderate road speeds are normal. If
you have a diesel engine, the normal operating range
should be between 35 and 70 psi (240 to 480 kPa).A reading in the low pressure zone may be caused by a
dangerously low oil level or other problem.
If you have a Caterpillar

diesel engine, also see your
Caterpillar
Operation & Maintenance Manual.
CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have your
vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.

2-88 Change Oil Light
The change oil light should
come on briefly as a bulb
check when you start the
engine. If the light doesn't
come on, have it serviced.
If the change oil soon light comes on and stays on after
you start the engine, have the oil changed.
For additional information, see ªEngine Oil, When to
Changeº in the Index. To reset the change oil light, see
ªGM Oil Life System
º in the Index.
Low Oil Level Light
This light should come on
as a check, when you start
your engine. If the light
fails to come on, have it
repaired as soon as possible
so you will be aware when
the oil level is low.
If this light comes on and stays on, it means your engine
is low on oil. You need to check the oil level right away.
See ªChecking Engine Oilº in the Index for further
information.