2007 DODGE RAM 2500 DIESEL cooling

“1” First
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE: Use caution when operating a heavily loaded
vehicle in “2” Second or “1” First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
WARNING!
Never use Park position on an automatic transmis-
sion as a substitute for the parking brake. Always
apply parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth (if equipped) speed
(Overdrive). The transmission will automatically shift
from Drive to Overdrive if the following conditions are
present:
•the transmission selector is in Drive;
•the engine coolant has reached normal operating tem-
perature;
•vehicle speed is above approximately 30 mph (48
km/h);
•the “TOW HAUL O/D OFF” switch has not been
activated;
•transmission has reached normal operating tempera-
ture.
270 STARTING AND OPERATING

When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
City Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
Trailer Towing Mirrors — If Equipped
These mirrors are designed with an adjustable mirror
head to provide a greater vision range when towing
extra-wide loads. To change position inboard or out-
board, the mirror head should be rotated (flipped Out or
In). A small blindspot mirror is integrated onto the main
mirror surface.
NOTE: Fold th e7x10inch trailer towing mirrors
rearward prior to entering an automated car wash.
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▫Front Axle Universal Drive Joints And Pivot
Bearings ............................398
▫ Body Lubrication .....................399
▫ Windshield Wiper Blades ................399
▫ Windshield Washers ...................399
▫ Exhaust System ......................400
▫ Cooling System .......................401
▫ Fan ...............................407
▫ Charge Air Cooler (Inter-Cooler) ..........408
▫ Hoses And Vacuum/Vapor Harnesses .......408
▫ Brake System ........................409
▫ Clutch Linkage .......................411
▫ Clutch Hydraulic System ................411 ▫
Rear Axle And 4X4 Front Driving
Axle Fluid Level ......................411
▫ Transfer Case — If Equipped .............412
▫ Manual Transmission — If Equipped .......412
▫ Automatic Transmission ................413
▫ Front Wheel Bearings ..................415
▫ Selection Of Lubricating Grease ...........416
▫ Noise Control System Required Maintenance &
Warranty ...........................417
▫ Appearance Care And Protection
From Corrosion ......................422

Fuses (Integrated Power Module) ...........426

Vehicle Storage ........................431

Replacement Light Bulbs .................432
376 MAINTAINING YOUR VEHICLE

•If an engine has been operating and the coolant is hot,
allow the engine to cool before you slowly loosen the
filler cap and relieve the pressure from the cooling
system.
•To avoid burns, remember that the engine components
will stay hot after the engine is shut off.
•Do not use gasoline or other flammable materials to
clean parts. Always use approved cleaning solvents.
•Relieve all pressure in the fuel, oil and cooling systems
before any lines, fittings or related items are removed
or disconnected. Be alert for possible pressure when
disconnecting any device from a system that utilizes
pressure. Do not check for pressure leaks with your
hand. High pressure oil or fuel can cause personal
injury.
WARNING!
Do not open the high pressure fuel system with the
engine running. Engine operation causes high fuel
pressure. High pressure fuel spray can cause serious
injury or death.
•Important: All maintenance other than that listed in
this manual, as well as some procedures listed here,
MUST be performed by your local Dodge Truck
Dealer. Your authorized Dodge Dealer has been
trained and has the necessary parts to maintain your
engine.
382 MAINTAINING YOUR VEHICLE

Always check the condition of the used oil. This can give
you an indication of some engine problems that might
exist.
•Thin, black oil indicates fuel dilution.
•Milky discoloration indicates coolant dilution.
Clean the area around the oil filter base. Remove the filter
from the underside of the vehicle using a cap style oil
filter wrench.
Clean the gasket surface of the filter mount. The filter
gasket can stick on the filter mount. Make sure it is
removed.
Change the engine oil filter with every engine oil change.
Only a high quality MOPAR filter should be used to
assure most efficient service.
CAUTION!
The filtering medium of other aftermarket filters
may disintegrate. Debris from failed filters may plug
the piston oil cooling nozzles, resulting in scuffed
pistons and engine failure.
CAUTION!
Fill the oil filter element with clean oil before
installation. Use the same type oil that will be used
in the engine. When filling the oil filter, prevent
foreign material from falling into the filter. Severe
engine damage may occur.
Apply a light film of lubricating oil to the sealing surface
of the filter gasket before installing the filter.
MAINTAINING YOUR VEHICLE 387
7

inspect the exhaust system each time the vehicle is raised
for lubrication or oil change. Replace as required.
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO) which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing CO, fol-
low the preceding safety tips.
Exhaust System Rubber Isolator and Loop-Type
Hanger — If Equipped
Inspect surfaces whenever the vehicle is hoisted for
rubber to metal separation or deep cracks. If, however,
excessively deep localized cracks are present, or any part
of the exhaust system abnormally contacts the under-
body hardware, the isolator and/or hanger should be
replaced.
Cooling System
WARNING!
You or others can be badly burned by hot coolant or
steam from your radiator. If you see or hear steam
coming from under the hood, don’t open the hood
until the radiator has had time to cool. Never try to
open a cooling system pressure cap when the radia-
tor is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before 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. Check the front of the A/C condenser for any
MAINTAINING YOUR VEHICLE 401
7

accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the condenser.
Check the coolant recovery bottle tubing for brittle rub-
ber, cracking, tears, cuts and tightness of the connection
at the bottle and radiator. Inspect the entire system for
leaks.
Extremely cold ambient temperature may require the
addition of a “winter front” 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.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.
402 MAINTAINING YOUR VEHICLE

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.
Cooling System — Drain, Flush and Refill
At the intervals shown on the Maintenance Schedules,
the system should be drained, flushed and refilled.
If the solution is dirty or contains a considerable amount
of sediment, clean and flush with a reliable cooling
system cleaner. Follow with a thorough rinsing to remove
all deposits and chemicals. Properly dispose of old
antifreeze solution.
Selection Of Coolant
Use only the manufacturers recommended coolant, refer
to Fluids, Lubricants and Genuine Parts for correct
coolant type.
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