2004 DODGE RAM 2500 DIESEL coolant temperature

²automatic transmission is in Park (P)
²vehicle speed is zero
²Applying the throttle will cancel fast idle
²If the engine is equipped with an aftermarket exhaust
brake (manual transmissions only), operating the ex-
haust brake at idle will greatly improve warm up rate
and will help keep the engine close to operating
temperature during extended idle.
Stopping The Engine
Idle the engine a few minutes before routine shutdown.
After full load operation, idle the engine 3 to 5 minutes
before shutting it down. This idle period will allow the
lubricating oil and coolant to carry excess heat away from
the combustion chamber, bearings, internal components,
and turbocharger. This is especially important for turbo-
charged, charge air cooled engines, like your Turbo Ram.
Driving
ConditionLoadTurbo-
charger
TemperatureIdle Time
(min.) Be-
fore Engine
Shutdown
Stop and
GoEmpty Cool Less than
One
Stop and
GoMedium One
Highway
SpeedsMedium Warm Two
City Traffic Maximum
GCWRThree
Highway
SpeedsMaximum
GCWRFour
Uphill
GradeMaximum
GCWRHot Five
STARTING AND OPERATING 215
5

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

²Highway Driving Ð
reduce your speed.
²Up Steep Hills Ð
select a lower transmission gear, but try and keep the
torque converter locked.
²Air Conditioning Ð
turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM............... 10psi(69kPa)
Full speed and load.............. 30psi(207 kPa)
CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage.
Do Not Operate The Engine With Failed Parts
Practically all failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:
²engine misfiring or vibrating severely
²sudden loss of power
²unusual engine noises
²fuel, oil or coolant leaks
STARTING AND OPERATING 217
5

²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW/HAULº switch has not been activated;
²transmission has reached normal operating tempera-
ture.
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).
Overdrive can be locked out by pressing the ªTOW/
HAULº button located on the selector lever. The ªTOW/
HAULº light will illuminate in the instrument cluster to
indicate that the switch has been activated. Pressing the
switch a second time restores the Overdrive function. If
the ªTOW/HAULº feature is desired, theªTOW/HAULº
button must be pressed each time the engine is started.NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable temperature. Refer also to the Note
under torque converter clutch, later in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the ªTOW/HAULº
and/or TRANS TEMP light(s) may illuminate and the
transmission may downshift out of Overdrive until the
transmission cools down. After cooldown, the transmis-
sion will resume normal operation.
When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 4±3±4 transmission shifting
STARTING AND OPERATING 221
5

Checking the vehicle while it's on level ground will also
improve the accuracy of the oil level readings. Add oil
only when the level on the dipstick is below the ªADDº
mark. The total capacity from the low mark to the high
mark is 2 quarts (1.9 liters).
Never operate the engine with oil level below the ªADDº
mark or above the upper ªSAFEº mark.Change Engine Oil
CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could dam-
age your engine.
Road conditions as well as your kind of driving affect the
interval at which your oil should be changed. Check the
following to determine if any apply to you:
²Frequent short trips where the engine does not achieve
full operating temperature (operating temperature de-
fined as 190É F (66É C ) coolant temperature).
²Extensive engine idling (over 10 minutes per hour of
operation) at ambient temperatures less than 32É F (0É
C).
326 MAINTAINING YOUR VEHICLE

NOTE:The same oil change interval is to be followed
for synthetic oil as for petroleum based oil. Also, syn-
thetic oil must meet the same performance specifications
as petroleum oil.Engine Oil Filter
Refer to Recommended Fluids, Lubricants and Genuine
Parts for the correct part number. The engine oil filter
should be changed ateveryengine oil change.
Engine Oil And Filter Ð Change
WARNING!
Hot oil can cause personal injury.
Operate the engine until the coolant temperature reaches
140ÉF (60ÉC). Shut the engine off. Remove the oil drain
plug.
Use a container that can hold at least 12 quarts (11.3
Liters) to hold the used oil.
328 MAINTAINING YOUR VEHICLE

Cooling System
Cooling System Maintenance
At the intervals shown in the Maintenance Schedules
Section of the manual, the system should be drained,
flushed and filled.
Inspection
Coolant protection checks should be made every 12
months (prior to the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant as specified.
Inspect the entire cooling system for leaks. Check the face
of the radiator for any accumulation of bugs, leaves, or
other foreign matter. If dirty, clean the radiator core with
a garden hose. With the engine OFF, gently spray water
from the back of the radiator core. Check coolant bottle
tube for condition and tightness of connections at coolant
bottle and radiator.Check the coolant pressure cap and coolant bottle for
proper vacuum sealing. With the engine at normal oper-
ating temperature, note the level of the coolant in the
coolant bottle. Without removing the pressure cap (with
the engine off), drain a small amount of coolant from the
radiator drain cock. If the coolant level in the coolant
bottle drops, the system is sealing properly.
Extremely cold ambient temperature may require the
addition of a ªwinter frontº for effective operation of the
cab heating/cooling system. Make certain that a percent-
age of the radiator is exposed for adequate air flow
through the charge air cooler and automatic transmission
oil cooler. The percentage of opening must be increased
with the increasing ambient air temperature and/or
engine load. If the cooling fan can be heard cycling
frequently, increase the size of the opening in the winter
front.
MAINTAINING YOUR VEHICLE 343
7

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