Initial Inspection and Diagnostic Overview
ENGINE COOLING SYSTEM OVERHEATINGEstablish what driving conditions caused the complaint. 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 recommended.
TRAILER TOWING
Consult Trailer Towing section of owners manual. Do not exceed limits.
AIR CONDITIONING; ADD-ON OR AFTER MARKET
These models are equipped with a "heavy duty" cooling system and therefore will accommodate add-on or aftermarket air conditioning. No modifications are necessary to the cooling system.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been performed on vehicle that may effect cooling system. This may be:
^ Engine adjustments (incorrect timing)
^ Slipping engine accessory drive belt(s)
^ Brakes (possibly dragging)
^ Changed parts (incorrect water pump rotating in wrong direction)
^ Reconditioned radiator or cooling system refilling (possibly under- filled or air trapped in system).
NOTE: If investigation reveals none of the previous items as a cause for an engine overheating complaint, refer to Cooling System Diagnosis charts.