1998 DODGE RAM 1500 coolant temperature

INTERNATIONAL VEHICLE
CONTROL & DISPLAY
SYMBOLS
DESCRIPTION - INTERNATIONAL SYMBOLS
The graphic symbols illustrated in the following
International Control and Display Symbols Chart are
used to identify various instrument controls. The
symbols correspond to the controls and displays that
are located on the instrument panel.
FASTENER IDENTIFICATION
DESCRIPTION
The SAE bolt strength grades range from grade 2
to grade 8. The higher the grade number, the greater
the bolt strength. Identification is determined by the
line marks on the top of each bolt head. The actual
bolt strength grade corresponds to the number of line
marks plus 2. The most commonly used metric bolt
strength classes are 9.8 and 10.9. The metric
strength class identification number is imprinted on
the head of the bolt. The higher the class number,
the greater the bolt strength. Some metric nuts are
imprinted with a single-digit strength class on the
nut face. Refer to the Fastener Identification and
Fastener Strength Charts (Fig. 5) and (Fig. 6).
INTERNATIONAL SYMBOLS
1 High Beam 13 Rear Window Washer
2 Fog Lamps 14 Fuel
3 Headlamp, Parking Lamps, Panel Lamps 15 Engine Coolant Temperature
4 Turn Warning 16 Battery Charging Condition
5 Hazard Warning 17 Engine Oil
6 Windshield Washer 18 Seat Belt
7 Windshield Wiper 19 Brake Failure
8 Windshield Wiper and Washer 20 Parking Brake
9 Windscreen Demisting and Defrosting 21 Front Hood
10 Ventilating Fan 22 Rear hood (Decklid)
11 Rear Window Defogger 23 Horn
12 Rear Window Wiper 24 Lighter
DRINTRODUCTION 5

Oils of the SAE 5W-40 grade number are preferred
when minimum temperatures consistently fall below
-15ÉC. (Fig. 5)
DESCRIPTION - POWER STEERING FLUID
MopartATF +4, Automatic Transmission Fluid is
required in the power steering system. Substitute
fluids can induce power steering system failure.
MopartATF +4, Automatic Transmission Fluid
when new is red in color. The ATF is dyed red so it
can be identified from other fluids used in the vehicle
such as engine oil or antifreeze. The red color is not
permanent and is not an indicator of fluid condition.
As the vehicle is driven, the ATF will begin to look
darker in color and may eventually become brown.
This is normal.ATF+4 also has a unique odor that
may change with age. Consequently, odor and color
cannot be used to indicate the fluid condition or the
need for a fluid change.
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACTYOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equiva-
lent ethylene glycol base coolant with organic corro-
sion inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37ÉC (-35ÉF). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solu-
tion.
CAUTION: MoparTAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Mixing of
coolants other than specified (non-HOAT or other
HOAT), may result in engine damage that may not
be covered under the new vehicle warranty, and
decreased corrosion protection.
COOLANT PERFORMANCE
The required ethylene-glycol (antifreeze) and water
mixture depends upon climate and vehicle operating
conditions. The coolant performance of various mix-
tures follows:
Pure Water-Water can absorb more heat than a
mixture of water and ethylene-glycol. This is for pur-
pose of heat transfer only. Water also freezes at a
higher temperature and allows corrosion.
100 percent Ethylene-Glycol-The corrosion
inhibiting additives in ethylene-glycol need the pres-
ence of water to dissolve. Without water, additives
form deposits in system. These act as insulation
causing temperature to rise to as high as 149ÉC
(300ÉF). This temperature is hot enough to melt plas-
Fig. 4 API RATING WRAP FIGURE
Fig. 5 DIESEL OIL VISCOSITY CHART
DRLUBRICATION & MAINTENANCE 0 - 3
FLUID TYPES (Continued)

tic and soften solder. The increased temperature can
result in engine detonation. In addition, 100 percent
ethylene-glycol freezes at -22ÉC (-8ÉF).
50/50 Ethylene-Glycol and Water-Is the recom-
mended mixture, it provides protection against freez-
ing to -37ÉC (-34ÉF). The antifreeze concentration
must alwaysbe a minimum of 44 percent, year-
round in all climates. If percentage is lower, engine
parts may be eroded by cavitation. Maximum protec-
tion against freezing is provided with a 68 percent
antifreeze concentration, which prevents freezing
down to -67.7ÉC (-90ÉF). A higher percentage will
freeze at a warmer temperature. Also, a higher per-
centage of antifreeze can cause the engine to over-
heat because specific heat of antifreeze is lower than
that of water.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
COOLANT SELECTION AND ADDITIVES
NOTE: Refer to the vehicle's coolant bottle to iden-
tify HOAT or Non-HOAT coolant. Non-HOAT coolant
is green in color.
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.
CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
DESCRIPTION - TRANSFER CASE
Recommended lubricant for the NV241 GENII,
NV271, NV243, NV244 GENII, and NV273 transfer
cases is MopartATF +4, Automatic Transmission
Fluid.
DESCRIPTION - AXLE
NOTE: DaimlerChrysler recommends using MoparT
lubricants or lubricants of equal quality.
FRONT AXLE
²C205F - MopartGear Lubricant 75W-90
²9 1/4 AA - MopartSynthetic Gear Lubricant
75W-90
REAR AXLE
²9 1/4 - MopartSynthetic Gear Lubricant 75W-
140
²10 1/2 AA - MopartSynthetic Gear Lubricant
75W-90
²11 1/2 AA - MopartSynthetic Gear Lubricant
75W-90
NOTE: Trac-LokTdifferentials require Limited Slip
Additive in the lubricant. Trac-RiteŸ differentials
DO NOT require Limited Slip Additive.
DESCRIPTION - MANUAL TRANSMISSION
NOTE: DaimlerChrysler recommends using MoparT
lubricants or lubricants of equal quality.
²NV3500 - MopartManual Transmission Lubri-
cant
²NV4500 - MopartSynthetic 75W85 Manual
Transmission Lubricant
²NV5600 - MopartManual Transmission Lubri-
cant
DESCRIPTION - AUTOMATIC TRANSMISSION
FLUID
NOTE: Refer to Service Procedures in this group for
fluid level checking procedures.
MopartATF +4, Automatic Transmission Fluid is
the recommended fluid for DaimlerChrysler auto-
matic transmissions.
Dexron II fluid IS NOT recommended. Clutch
chatter can result from the use of improper
fluid.
MopartATF +4, Automatic Transmission Fluid
when new is red in color. The ATF is dyed red so it
can be identified from other fluids used in the vehicle
such as engine oil or antifreeze. The red color is not
permanent and is not an indicator of fluid condition.
As the vehicle is driven, the ATF will begin to look
darker in color and may eventually become brown.
This is normal.ATF+4 also has a unique odor that
may change with age. Consequently, odor and color
cannot be used to indicate the fluid condition or the
need for a fluid change.
0 - 4 LUBRICATION & MAINTENANCEDR
FLUID TYPES (Continued)

DESCRIPTION SPECIFICATION
REAR AXLE   .03 L (1 oz)
9 1/4 2.32 L (4.9 pts.)***
10 1/2 AA 2.25 L (4.75 pts.)
11 1/2 AA 3.62 L (7.65 pts)
*** With Trac-Lok add 118 ml (4 oz.) of Limited Slip
Additive.
** Includes 0.9L (1.0 qts.) for coolant reservoir.
*Nominal refill capacities are shown. A variation may
be observed from vehicle to vehicle due to
manufacturing tolerance and refill procedure.
MAINTENANCE SCHEDULES
DESCRIPTION
DESCRIPTION
Maintenance Schedule Information not included in
this section, is located in the appropriate Owner's
Manual.
There are two maintenance schedules that show
therequiredservice for your vehicle.
First is ScheduleªBº. It is for vehicles that are
operated under the conditions that are listed below
and at the beginning of the schedule.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
²If equipped for and operating with E-85
(ethanol) fuel.
NOTE: If ANY of these apply to the vehicle then
change the engine oil every 3,000 miles (5 000 km)
or 3 months, whichever comes first and follow
schedule ªBº of the(Maintenance Schedules(sec-
tion of this manual.
NOTE: Most vehicles are operated under the condi-
tions listed for Schedule(B(.
Second is ScheduleªAº. It is for vehicles that are
not operated under any of the conditions listed under
Schedule9B9.Use the schedule that best describes the driving
conditions. Where time and mileage are listed, follow
the interval that occurs first.
CAUTION: Failure to perform the required mainte-
nance items may result in damage to the vehicle.
At Each Stop for Fuel
²Check the engine oil level about 5 minutes after
a fully warmed engine is shut off. Checking the oil
level while the vehicle is on level ground will
improve the accuracy of the oil level reading. Add oil
only when the level is at or below the ADD or MIN
mark.
²Check the windshield washer solvent and add if
required.
Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect the battery and clean and tighten the
terminals as required.
²Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission
and add as needed.
²Check all lights and all other electrical items for
correct operation.
At Each Oil Change
²Change the engine oil filter.
²Inspect the exhaust system.
²Inspect the brake hoses.
²Inspect the CV joints (if equipped) and front sus-
pension components.
²Check the automatic transmission fluid level.
²Check the manual transmission fluid level.
²Check the coolant level, hoses, and clamps.
²Rotate the tires at each oil change interval
shown on Schedule ªAº 10 000 km (6,000 miles) or
every other interval shown on Schedule ªBº 10 000
km (6,000 miles).
Tire Rotation
²Rotate the tires at 6,000 miles (10 000 km).
Schedule ªBº
Follow schedule ªBº if you usually operate your
vehicle under one or more of the following conditions.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
0 - 6 LUBRICATION & MAINTENANCEDR
FLUID CAPACITIES (Continued)

Miles 102,000 108,000 114,000 120,000
(Kilometers) (163 000) (173 000) (182 000) (192 000)
[Months] [102] [108] [114] [120]
Change engine oil and engine oil filter. X X X X
Drain and refill transfer case fluid (4X4). X
Flush and replace engine coolant, if not done at 60 mos. X
Lubricate outer tie rod ends 2500/3500 (4X4) models
only.XXX X
Inspect brake linings. X
Inspect auto tension drive belt and replace if required
(3.7L/4.7L/5.7L).X³X³
Replace ignition cables.X
Replace engine air cleaner filter.X
Replace spark plugs.X
Inspect PCV Valve, replace as necessary X*
* This maintenance is recommended by the manu-
facture to the owner but is not required to maintain
the emissions warranty.
³ This maintenance is not required if previously
replaced.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
WARNING: You can be badly injured working on or
around a motor vehicle. Do only that service work
for which you have the knowledge and the right
equipment. If you have any doubt about your ability
to perform a service job, take your vehicle to a
competent mechanic.
MAINTENANCE SCHEDULES Ð 24±VALVE
CUMMINS TURBO DIESEL
There are two maintenance schedules that show
therequiredservice for your vehicle.
First is ScheduleªBº. It is for vehicles that are
operated under the conditions that are listed below
and at the beginning of the schedule.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
NOTE: Most vehicles are operated under the condi-
tions listed for Schedule(B(.
Second is ScheduleªAº. It is for vehicles that are
not operated under any of the conditions listed under
Schedule9B9.
Use the schedule that best describes your driving
conditions. Where time and mileage are listed, follow
the interval that occurs first.
CAUTION: Failure to perform the required mainte-
nance items may result in damage to the vehicle.At Each Stop for Fuel
²Check the engine oil level about 15 minutes
after a fully warmed engine is shut off. Checking the
oil level while the vehicle is on level ground will
improve the accuracy of the oil level reading. Add oil
only when the level is at or below the ADD or MIN
mark.
²Check the windshield washer solvent and add if
required.
²Drain water from the fuel filter.
0 - 12 LUBRICATION & MAINTENANCEDR
MAINTENANCE SCHEDULES (Continued)

Once a Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect the batteries and clean and tighten the
terminals as required.
²Check the fluid levels of coolant reservoir, brake
master cylinder, power steering and transmission
and transfer case (if equipped), add as needed.
²Check Filter MinderŸ. Replace air cleaner
filter element if necessary.
²Check all lights and all other electrical items for
correct operation.
At Each Oil Change
²Change the engine oil filter.
²Inspect the exhaust system.
²Inspect the brake hoses.
²Inspect the CV joints (if equipped) and front sus-
pension components.
²Check the automatic transmission fluid level.
²Check the manual transmission fluid level.
²Check the coolant level, hoses, and clamps.
Tire Rotation
²Rotate the tires every 7,500 miles (12 000 km).
Engine Oil Change Chart Notes
²LTier 1 EPA (250 hp or 305 hp) Engines Only
(see engine data label for your engine type)
²² California LEV (235 hp) Engines Only (see
engine data label for your engine type)
Schedule ªBº
Follow schedule ªBº if you usually operate your
vehicle under one or more of the following conditions.
²Day or night temperatures are below 0É C (32É
F).
²Stop and go driving.
²Extensive engine idling.
²Driving in dusty conditions.
²Short trips of less than 16 km (10 miles).
²More than 50% of your driving is at sustained
high speeds during hot weather, above 32É C (90É F).
²Trailer towing.
²Taxi, police, or delivery service (commercial ser-
vice).
²Off-road or desert operation.
Miles 3,750 7,500 11,250 15,000 18,750
(Kilometers) (6 000) (12 000) (18 000) (24 000) (30 000)
Change engine oil and engine oil filter. X² XL²X²XL²X²
Lubricate outer tie rod ends 2500/3500
(4X4) models only.XX
Inspect water pump weep hole for
blockage.X
Replace fuel filter element. Clean the water
in fuel sensor.X
Change rear axle fluid. X
Change front axle fluid (4X4). X
Inspect brake linings.X
Inspect and adjust parking brake if
necessary.X
DRLUBRICATION & MAINTENANCE 0 - 13
MAINTENANCE SCHEDULES (Continued)

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE..................1
DESCRIPTION - COOLING SYSTEM FLOW -
5.9L DIESEL..........................3
DESCRIPTION - HOSE CLAMPS...........3
OPERATION
OPERATION - COOLING SYSTEM.........5
OPERATION - HOSE CLAMPS............5
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)...................5
DIAGNOSIS AND TESTING - COOLING
SYSTEM - TESTING FOR LEAKS..........5
DIAGNOSIS AND TESTING - COOLING
SYSTEM DIESEL ENGINE................7
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS............................10
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLANT
LEVEL CHECK........................17STANDARD PROCEDURE - COOLING
SYSTEM CLEANING/REVERSE FLUSHING . . 17
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM - ALL GAS ENGINES . . . 17
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM - ALL GAS ENGINES . . . 18
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 18
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM 5.9L DIESEL ENGINE . . . 19
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................19
SPECIFICATIONS
TORQUE............................19
SPECIFICATIONS -....................20
SPECIAL TOOLS
COOLING...........................20
ACCESSORY DRIVE......................21
ENGINE...............................30
TRANSMISSION.........................67
COOLING
DESCRIPTION
DESCRIPTION - COOLING SYSTEM FLOW
3.7L/4.7L/5.7L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.The cooling system provides a means of heating
the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant through the system. The
coolant recovery/reserve system utilizes an ambient
overflow bottle (Fig. 2).
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
DRCOOLING 7 - 1

OPERATION
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
All engines utilize an ambient overflow bottle for
coolant recovery/reserve.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, only use constant tension clamp pliers
designed to compress the hose clamp.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The Engine Control Module (ECM) has been pro-
grammed to monitor certain cooling system compo-
nents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the electronically controlled viscous fan clutch circuit,
a Diagnostic Trouble Code (DTC) can be set.
²If fan speed is not detected a DTC will be set.
²Coolant temperature sensor circuit problems can
set a DTC.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the ECM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ACCESSING DIAGNOSTIC TROUBLE CODES
To read DTC's and to obtain cooling system data,
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
ERASING TROUBLE CODES
After the problem has been repaired, use the
DRBIIItscan tool to erase a DTC. Refer to the
appropriate Powertrain Diagnostic Procedures ser-
vice information for operation of the DRBIIItscan
tool.
DIAGNOSIS AND TESTING - COOLING SYSTEM
- TESTING FOR LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate the engine until the radi-
ator upper hose is warm to the touch. Aim the com-
mercially available black light tool at the components
to be checked. If leaks are present, the black light
will cause the additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
DRCOOLING 7 - 5
COOLING (Continued)