Dodge ram truck 3500 1996 Service Manual page 309

B R • • — — — • — —
D I A G N O S I S AND T E S T I N G (Continued)
COOLING SYSTEM DIAGNOSIS—DIESEL ENGINE—CONTINUED
COOLING SYSTEM 7 - 25
CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE HEATER
PERFORMANCE. MAYBE
ACCOMPANIED BY LOW
GAUGE READING
1. Diesel engines, due to their
inherent efficiency are slower to
warm up than gasoline powered
engines, and will operate at
lower temperatures when the
vehicle is unloaded.
2. Coolant level low.
3. Obstructions in heater hose
fittings at engine.
4. Heater hose kinked.
5. Water pump is not pumping
water to heater core. When the
engine is fully warmed up, both
heater hoses should be hot to
the touch. If only one of the
hoses is hot, the water pump
may not be operating correctly.
The accessory drive belt may
also be slipping causing poor
water pump operation.
1. The low gauge reading may be normal.
Refer to Thermostats in the manual text
for information. See Thermostat
Diagnosis - Diesel Engine.
2. Refer to Testing Cooling System For
Leaks in the manual text. Repair as
necessary.
3. Remove heater hoses at both ends and
check for obstructions. Repair as
necessary.
4. Locate kinked area and repair as
necessary.
5. Refer to Water Pumps in this group.
Repair as necessary. If a slipping belt is
detected, refer to Engine Accessory Drive
Belts in this group. Repair as necessary.
HEAT ODOR 1. Various heat shields are used at
certain drive line components.
One or more of these shields
may be missing.
2. Is temperature gauge reading
above the normal range?
3. Is cooling fan operating
correctly?
4. Has undercoating been applied
to any unnecessary component?
1. Locate missing shields and replace or
repair as necessary.
2. Refer to the previous Temperature
Gauge Reads High in these Diagnosis
Charts. Repair as necessary.
3. Refer to Cooling System Fan in this
group for diagnosis. Repair as necessary.
4. Clean undercoating as necessary.
J9507-61