Dodge dakota 2002 Service Manual page 302

DR
COOLING (Continued)
CONDITION
DETONATION OR PRE-
IGNITION (NOT CAUSED BY
IGNITION SYSTEM). GAUGE
MAY OR MAY NOT BE
READING HIGH
HOSE OR HOSES COLLAPSE
WHILE ENGINE IS RUNNING
(b) Hose between coolant
reserve/overflow tank and
radiator is kinked. Repair as
necessary.
(c) Vent at coolant reserve/
overflow tank is plugged. Clean
vent and repair as necessary.
NOISY VISCOUS FAN/DRIVE
POSSIBLE CAUSES
1. Engine overheating.
2. Freeze point of coolant not
correct. Mixture is too rich or too
lean.
1. Vacuum created in cooling
system on engine cool-down is
not being relieved through
coolant reserve/overflow system.
1. Fan blades loose.
2. Fan blades striking a
surrounding object.
3. Air obstructions at radiator or
air conditioning condenser.
4. Thermal viscous fan drive has
defective bearing.
5. A certain amount of fan noise
may be evident on models
equipped with a thermal viscous
fan drive. Some of this noise is
normal.
COOLING
CORRECTION
1. Check reason for overheating and
repair as necessary.
2. Check coolant concentration. (Refer to
LUBRICATION & MAINTENANCE/FLUID
TYPES - DESCRIPTION).
1. (a) Radiator cap relief valve stuck.
(Refer to 7 - COOLING/ENGINE/
RADIATOR PRESSURE CAP -
DIAGNOSIS AND TESTING). Replace if
necessary
(d) Reserve/overflow tank is internally
blocked or plugged. Check for blockage
and repair as necessary.
1. Replace fan blade assembly. (Refer to 7
- COOLING/ENGINE/RADIATOR FAN -
REMOVAL)
2. Locate point of fan blade contact and
repair as necessary.
3. Remove obstructions and/or clean
debris or insects from radiator or A/C
condenser.
4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/
ENGINE/FAN DRIVE VISCOUS CLUTCH
- REMOVAL).
5. (Refer to 7 - COOLING/ENGINE/FAN
DRIVE VISCOUS CLUTCH -
DESCRIPTION) for an explanation of
normal fan noise.
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