2004 DODGE RAM 2500 DIESEL engine overheat

12. ABS Warning Light
This light monitors the Anti-Lock Brake System
which is described elsewhere in this manual. This
light will come on when the ignition key is turned to the
ON position and may stay on for five seconds. If the ABS
light remains on or comes on during driving, it indicates
that the anti-lock portion of the brake system is not
functioning and that service is required. See your autho-
rized dealer immediately. The ABS light could also
illuminate during loss of traction and remain illuminated
until the brake pedal is pressed.
13. Temperature Gauge
The temperature gauge indicates engine coolant
temperature. Any reading within the normal
range indicates that the cooling system is operat-
ing satisfactorily. The gauge needle will likely indicate a
higher temperature when driving in hot weather, up
mountain grades, in heavy traffic, or when towing a
trailer. If the needle rises to the ª245ÉFº mark, stop thevehicle, shift into N (Neutral), and increase the engine
idle speed for 2 to 3 minutes. If the temperature reading
does not return to normal, shut your engine OFF and
allow it to cool. Seek authorized service immediately. See
Cooling System information in the section on ªMaintain-
ing Your Vehicle.º
CAUTION!
Do not leave your vehicle unattended with the
engine running as you would not be able to react to
the temperature indicator if the engine overheats.
NOTE:Engine idle speed will automatically increase to
1000 rpm at elevated coolant temperatures to improve
engine cooling.
146 UNDERSTANDING YOUR INSTRUMENT PANEL

speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette
smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation isencountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
UNDERSTANDING YOUR INSTRUMENT PANEL 197
4

Engine Speed Control
CAUTION!
Prevent overspeeding the engine going down hill.
When descending steep grades, use a combination of
gears and service brakes to control vehicle/engine
speed. Overspeed can cause severe engine damage.
Operating Precautions
Avoid Overheating The Engine
The temperature of the coolant (a mixture of 50%
ethylene-glycol and 50% water) must not exceed the
normal range of the temperature gauge (240ÉF/116ÉC)
with a 16 psi (110 kPa) radiator cap.
Usually the coolant temperature indicated during opera-
tion will be to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low coolant temperature below
the normal range on the gauge (140ÉF/60ÉC) can be
harmful to the engine. Low coolant temperature can
cause incomplete combustion which allows carbon and
varnish to form on piston rings and injector nozzles.
Also, the unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the engine.
Cooling System Tips Ð Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
²City Driving Ð
when stopped, put transmission in neutral and increase
engine idle speed.
NOTE:The engine speed will automatically increase to
1000 RPM at elevated coolant temperature to improve
engine cooling.
216 STARTING AND OPERATING

occurs, press the ªTOW/HAULº button. This will im-
prove performance and reduce the potential for transmis-
sion overheating or failure due to excessive shifting.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
high gear. When the vehicle speed drops or during
acceleration when the transmission downshifts to second
gear, the clutch automatically disengages.
NOTE:The torque converter clutch will not engage
until the transmission fluid and engine coolant are warm
[usually after 1-3 miles (1.6 ± 4.8 km) of driving]. Because
the engine speed is higher when the torque converter
clutch is not engaged, it may seem as if the transmission
is not shifting into Overdrive when cold. This is normal.Pressing the ªTOW/HAULº button, when the transmis-
sion is sufficiently warm, will demonstrate that the
transmission is able to shift into and out of overdrive.
NOTE:If the vehicle has not been driven in several
days, the first few seconds of operation after shifting the
transmission into gear may seem sluggish. This is due to
the fluid partially draining from the torque converter into
the transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds of shifting from Park into
any other gear position.
Manual Transmission ± 5±Speed (NV- 4500) Ð If
Equipped
NOTE:The parking brake should be engaged before
leaving the vehicle, especially on an incline.
222 STARTING AND OPERATING

²Highway DrivingÐreduce your speed.
²Air ConditioningÐturn it off temporarily.
²Hilly TerrainÐTurn overdrive off.
See Cooling System Operating information in the Service
and Maintenance section of this manual for more infor-
mation.
Automatic Transmission Oil Temperature Warning
Light
All vehicles with heavy duty transmission oil cooling are
equipped with a transmission sump oil temperature
sensor and warning light. If elevated transmission tem-
peratures are encountered, the engine controller will
select the most desirable gear until the transmission
temperatures are reduced. If transmission oil tempera-
tures continue to rise, a warning light located in theinstrument cluster will illuminate. If this should occur,
stop the vehicle, shift to Neutral, and run the engine at
idle or faster until the light goes off.
Towing With An Automatic Transmission
Vehicles equipped with an automatic transmission may
shift into and out of Overdrive, or a lower gear, when
driving in hilly areas, when heavily loaded, or when
towing into heavy winds.
When this condition occurs, press the ªTOW/HAULº
button or shift into a lower gear to prevent excessive
transmission wear and/or overheating, and to provide
better engine braking.
NOTE:Do not exceed the following RPM while manu-
ally downshifting:
²5.9L Diesel Engines 3200 RPM.
STARTING AND OPERATING 281
5

NOTE:During snowplow usage on vehicles equipped
with an overhead console module, the outside tempera-
ture display will show higher temperatures than the
outside ambient temperature. The higher displayed tem-
perature is due to blocked or reduced airflow to the
underhood ambient temperature sensor by the snow-
plow. This is common and outside temperature display
operation will return to normal when the snowplow is
removed.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer's instructions.
Keep all snowplow electrical connections and battery
terminals clean and free of corrosion.
When plowing snow, to avoid transmission and driv-
etrain damage, the following precautions should be ob-
served.
²Operate with transfer case in 4L when plowing small
or congested areas where speeds are not likely to
exceed 15 mph (24 km/h). At higher speeds operate in
4H.
²Vehicles with 48RE transmissions should use 4L range
when plowing deep or heavy snow for extended
periods of time to avoid transmission overheating.
²Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission.
STARTING AND OPERATING 285
5

Coolant bottle level check
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant on the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool overheated engine! The coolant is under pres-
sure and severe scalding could result.
Drain, Flush And Refill
At intervals shown on the Maintenance Schedules, the
system should be drained, flushed and refilled. Refer to
your dealer or consult a service manual for proper
procedures.
Adding Coolant
When adding coolant or refilling system, a 50% solution
of ethylene glycol antifreeze coolant in water should be
used. Higher concentrations (not to exceed 65%) are
required if temperatures below -34 ÉF (-37 ÉC) are antici-
pated. Use only high purity water such as distilled or
deionized water when mixing the water/antifreeze solu-
tion. The use of lower quality water will reduce the
amount of corrosion protection in the engine cooling
system. Please note that it is the owner's responsibility to
maintain the proper level of protection against freezing
according to the temperatures occurring in the area
where the vehicle is operated.
344 MAINTAINING YOUR VEHICLE

NOTE:Mixing coolant types will decrease the life of the
engine coolant and will require more frequent coolant
changes.
When additional coolant is needed to maintain the
proper level, add the recommended concentration of
antifreeze and water to the overflow bottle. Do not
overfill.
NOTE:Failure to follow the antifreeze concentration
and replacement recommendations, or failure to use
antifreeze formulated to prevent corrosion of all cooling
system metals, may result in radiator plugging, overheat-
ing, or cooling system leaks such as in core hole plugs.WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool an overheated engine. The coolant is under
pressure and severe scalding could result.
Recommended Engine Coolant
Refer to Recommended Fluids, Lubricants and Genuine
Parts for the correct Fluid type.
MAINTAINING YOUR VEHICLE 345
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