Engine Cooling System Symptom Diagnosis
DIAGNOSTIC PROCEDURES
| Condition | Possible Cause | Action |
|---|---|---|
| Engine overheats (Radiator fan operates) | Loose or broken accessory drive belt | Check accessory drive belt, see ACCESSORY DRIVE BELT TENSION INSPECTION . |
| Not enough coolant | Check coolant level and add if necessary, see COOLANT LEVEL CHECK . | |
| Faulty thermostat | Check thermostat, see THERMOSTAT INSPECTION . | |
| Faulty water pump | Check water pump, see WATER PUMP INSPECTION . | |
| Dirty or bent radiator fins | Clean or remedy, see RADIATOR ON-VEHICLE INSPECTION AND CLEANING . | |
| Check cooling system for leakage on cooling system | Check cooling system for leakage, see ENGINE COOLING SYSTEM INSPECTION . | |
| Clogged radiator | Replace radiator, see RADIATOR REMOVAL AND INSTALLATION . | |
| Faulty radiator cap | Check radiator cap, see ENGINE COOLING SYSTEM INSPECTION . | |
| Dragging brakes | Check brake, see. BRAKE SYMPTOM DIAGNOSIS | |
| Slipping clutch | Check clutch, see CLUTCH SYSTEM SYMPTOM DIAGNOSIS . | |
| Poor charged battery | Check battery, see BATTERY INSPECTION . | |
| Poor electricity generated by generator | Check generator, see GENERATOR TEST . | |
| Faulty ECT sensor | Check ECT sensor, see ECT SENSOR INSPECTION . | |
| Faulty radiator cooling fan motor | Check radiator cooling fan motor, see RADIATOR COOLING FAN ASSEMBLY ON-VEHICLE INSPECTION . | |
| Faulty ECM | Check ECM and its circuit, see. INSPECTION OF ECM AND ITS CIRCUITS | |
| Faulty radiator cooling fan relay | Check radiator cooling fan relay, see CONTROL RELAY INSPECTION . | |
| Faulty wiring or grounding | Repair wiring . | |
| Equipped with too many additional electrical part(s) | Remove electrical parts . | |
| Engine overheats (Radiator fan does not operate) | Fuse blown | Check fuse . |
| Faulty radiator cooling fan relay | Check radiator cooling fan relay, see CONTROL RELAY INSPECTION | |
| Faulty ECT sensor | Check ECT sensor, see ECT SENSOR INSPECTION . | |
| Faulty radiator cooling fan motor | Check radiator cooling fan motor, see RADIATOR COOLING FAN ASSEMBLY ON-VEHICLE INSPECTION . | |
| Faulty wiring or grounding | Repair wiring . | |
| Faulty ECM | Check ECM and its circuit, see INSPECTION OF ECM AND ITS CIRCUITS . |