Diagnosis And Testing - Preliminary Checks - Dodge dakota 2002 Service Manual

7 - 10 COOLING
COOLING (Continued)
CONDITION
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED)
INADEQUATE HEATER
PERFORMANCE. GAUGE MAY OR
MAY NOT READ LOW.
HEAT ODOR
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
• PROLONGED IDLE
• VERY HIGH AMBIENT TEMPERATURE
• SLIGHT TAIL WIND AT IDLE
• SLOW TRAFFIC
• TRAFFIC JAMS
• HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
• Idle with A/C off when temperature gauge is at
end of normal range.
• Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
POSSIBLE CAUSES
1. Radiator and/or A/C condenser
air flow obstructed.
2. Electronically controlled viscous
fan drive not working.
3. Air seals around radiator
damaged or missing.
1. Heavy duty cooling system, and
cooler ambient temperatures.
2. Obstruction in heater hoses.
3. Electronically controlled viscous
fan stuck on
4. Water pump damaged.
1. Damaged or missing drive line
heat shields.
2. Electronically controlled viscous
fan drive damaged.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect the cooling system.
This may be:
• Engine adjustments (incorrect timing)
• Slipping engine accessory drive belt(s)
• Brakes (possibly dragging)
• Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
• Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
• Service to electrically controlled viscous fan
clutch
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to COOLING SYSTEM DIAGNOSIS
CHART BELOW.
These charts are to be used as a quick-reference
only. Refer to COOLING SYSTEM DIAGNOSIS
CHART
CORRECTION
1. Remove obstruction and/or clean.
2. Check fan drive. (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
3. Inspect air seals, repair or
replace as necessary.
1. None. Normal condition.
2. Remove hoses, remove
obstruction.
Check fan drive. (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS
AND TESTING)
4. Replace water pump.
1. Repair or replace damaged or
missing heat shields.
2. Check thermal viscous fan drive.
(Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DIAGNOSIS AND TESTING)
DR