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.
Engine Alarm and Automatic Shutdown
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 about 25–30 seconds.
There is also an engine shutdown light to indicate that
the engine will shut down. SeeEngine Shutdown
Warning Light on page 3-39.
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.
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•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.)
•The voltmeter charge indicator gage tells you the
condition of your battery’s charge. The gage
should be in the center area during engine
operation. The red area on the left indicates an
undercharge condition; the red area on the
right indicates an overcharge. If the gage is in
either red area, have the battery and charging
system checked right away.Notice:For diesel engines, don’t allow the engine
to operate at low idle for more than ve minutes.
This can cause low engine operating temperatures
which can affect engine operation and reduce
engine life. Engine idle speed should be increased
to 1200 rpm whenever extended idle is required.
Once started, the engine should be placed under
load to allow the engine coolant temperature
to reach 150°F (66°C) before shutting off the engine.
Engine Coolant Heater
If your vehicle has this
feature, the plug-in
receptacle is located under
the driver’s door.
In very cold weather, 0°F (−18°C) or colder, the engine
coolant heater can help. You’ll get easier starting
and better fuel economy during engine warm-up.
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Rear Heating System
If your vehicle has a rear
heater, the thumbwheel for
this feature is located on
the headliner.
To increase and decrease the flow of heated air to
the rear floor vents, turn the thumbwheel to the
desired fan speed. To turn the fan off, turn the
thumbwheel down.
Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly – and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
3-23
Low Coolant Warning Light
You have a low coolant
warning light. If this light
comes on, your system is
low on coolant and the
engine may overheat.
The warning light should come on briefly, as a check,
when you turn on the ignition.
When it comes on, you will also hear a warning tone at
several beats per second for 10 seconds. SeeEngine
Coolant (Gas and DURAMAX™ engines) on page 5-32
orEngine Coolant (Caterpillar
®Diesel Engines) on
page 5-35and have your vehicle serviced as soon as
you can.
This light may also come on if your vehicle is equipped
with the automatic engine shutdown system and
engine shutdown has begun. SeeEngine Alarm and
Automatic ShutdownunderStarting Your Diesel Engine
on page 2-14.
Wait to Start Indicator
If your vehicle has the DURAMAX™ 6600, you will have
glow plugs. If your vehicle has the DURAMAX™ 7800,
you will have glow plugs and an inlet heater. If your
vehicle has a Caterpillar
®engine, you will have an inlet
heater.
The light in the center of
the instrument panel will
come on when the
inlet heater is on and the
ignition key is in RUN.
Wait until the indicator light turns off before turning the
ignition key to START.
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Change Engine Oil Light
The change engine 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 engine oil light comes on and stays on
after you start the engine, have the oil changed.
For additional information on when to change engine oil
for gasoline engines or DURAMAX™ diesel engines,
seeEngine Oil (Caterpillar
®Diesel Engine) on page 5-20
orEngine Oil (Gasoline Engine) on page 5-20or
Engine Oil (DURAMAX™ Diesel) on page 5-25. To reset
the change engine oil light, seeEngine Oil
(Caterpillar
®Diesel Engine) on page 5-20orEngine Oil
(Gasoline Engine) on page 5-20orEngine Oil
(DURAMAX™ Diesel) on page 5-25.
Engine Overspeed Warning Light
If your vehicle has this
light, it will come on if your
engine is operating at
too many revolutions per
minute (rpm).
It will also come on for a moment as a check when you
start your engine.
If it comes on when you’re driving, reduce your engine
speed immediately.
Engine Shutdown Warning Light
If your vehicle has the
engine shutdown feature,
this light will come on
when engine shutdown
is active.
For more information, seeEngine Alarm and Automatic
ShutdownunderStarting Your Diesel Engine on
page 2-14.
3-39
Low Washer Fluid Warning Light
This light will come on
when your vehicle is low
on windshield washer fluid.
For more information, seeWindshield Washer Fluid on
page 5-44.
Check Gages Warning Light
This light will come on as
you’re starting the engine,
just as a check.
If this light comes on and stays on while you are driving.
it means that either your engine coolant temperature
gage or your engine oil pressure gage may be showing
a reading in the warning zone.When the check gages light comes on, you will also
hear a warning tone. The tone and the light will
stay activated until the problem is corrected.
This light may also come on if your vehicle is equipped
with the optional automatic engine shutdown system
and engine shutdown has begun. SeeEngine Alarm and
Automatic ShutdownunderStarting Your Diesel
Engine on page 2-14.
Fuel Gage
Your fuel gage is located
on the right side of your
instrument panel cluster.
When the ignition is on, your fuel gage lets you know
about how much fuel you have left. When the gage first
shows empty, you’ll still have a little fuel left, but you
should get more fuel soon.
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Air Filter Restriction Indicator
If your vehicle has this
feature, the gage is
located above the
switchbank in the center of
the instrument panel. It
monitors the engine
air filter.
As the filter gets dirty, the yellow indicator will begin to
rise. When it reaches 25 inches of vacuum on the
scale, the filter should be replaced.
After replacing the filter, reset the gage by pressing in
the yellow reset button at the bottom of the gage.
If you have a Caterpillar
®diesel engine, also see your
Caterpillar®Operation & Maintenance Manual.
Air Pressure Gage
If your vehicle has air
brakes, the air pressure
gage is located above the
switchbank in the center
of the instrument panel.
This gage shows the air pressure for both your front
and rear brake systems.
If the needle on the gage indicates that the air pressure
is below 60 to 75 psi (415 to 517 kPa), the low air
warning light will come on. An alarm will also sound if
this happens.
The yellow pointer shows the pressure available for the
front system, while the green pointer shows pressure
for the rear. There should be no more than 4 psi
(28 kPa) difference showing between the systems.
Don’t drive until both pointers are showing at least
115 psi (793 kPa), so you’ll have enough air if you need
to apply your brakes.
3-44
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brakes. See “Parking Brake” if necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P), if equipped, or NEUTRAL (N). If
the starter works in any other position, your vehicle
needs service.
Automatic Transmission Shift Indicator
Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is
harder to turn or has too much free play, or if there are
strange sounds when turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp or for
the tone alarm, or changes in braking action, such as
repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Make sure air
brake system reservoirs are drained daily with full
system air pressure, and check system for leaks. Any of
these conditions could indicate the need for brake
system inspection and/or service.
Engine Cooling System Service
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
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