Inspection
- Check each part for cracks, damage or wear, and replace the coolant pump assembly if necessary.
- Check the bearing for damage, abnormal noise and sluggish rotation, and replace the coolant pump assembly if necessary.
- Check for coolant leakage. If coolant leaks from hole, the seal is defective. Replace the coolant pump assembly. NOTE: A small amount of "weeping" from the bleed hole is normal.
Troubleshooting
Water Pump
| Symptoms | Possible Causes | Remedy | ||
|---|---|---|---|---|
| Coolant leakage | From the bleed hole of the water pump | Visually check | Check leaks after about ten-minute warming up. | If coolant still leaks, replace a water pump. |
| If leakage stops, reuse the water pump (Do not replace the pump with a new one). | ||||
| From gaskets or bolts | Check the tightening of the water pump mounting bolts. | Retighten the mounting bolts. | ||
| Check damage of gaskets or inflow of dust. | Replace the gasket and clean dust off. | |||
| From outer surface of water pump | Check the material or any cracks of the water pump. | Poor material. If any crack found, replace the water pump. | ||
| Noise | From bearings From mechanical seals Impeller interference | Inspection with a stethoscope | After starting the engine, check noise with a stethoscope. | If there is no noise, reuse the water pump (do not replace it). |
| If there is any noise from the water pump, remove the drive belt and recheck. | ||||
| Inspection after removing a drive belt | After removing a water pump and a drive belt, check noise again. | If there is noise, reuse the water pump. Check other drive line parts. | ||
| If there is no noise, replace the water pump with a new one. | ||||
| Inspection after removing a water pump | After removing a water pump and a drive belt, check noise again. | If there is any interference between them, replace the water pump with a new one. | ||
| Overheating | Damaged impeller Loosened impeller | Loosened impeller | Corrosion of the impeller wing | Check engine coolant. Poor coolant quality / Maintenance check |
| Impeller separation from the shaft | Replace the water pump. | |||
WATER PUMP TROUBLESHOOTING CHART
| Symptoms | Possible Causes | Remedy | ||
|---|---|---|---|---|
| Coolant leakage | From the thermostat gasket | Check the mounting bolts | Check the torque of the mounting bolts | Retighten the bolts and check leakage again. |
| Check the gasket for damage | Check gasket or seal for damage | Replace gaskets and reuse the thermostat. | ||
| Cooled excessively | Low heater performance (cool air blows out) Thermogauge indicates 'LOW' | Visually check after removing the radiator cap. | Insufficient coolant or leakage. | After refilling coolant, recheck. |
| GDS check & Starting engine | Check DTCs Check the fan motor performance as temperature varies. Check connection of the fan clutch or the fan motor. * If the fan clutch is always connected, there will be a noise at idle. | Check the engine coolant sensor, wiring and connectors. Check the fan motor, the relay and the connector. Replace the components. | ||
| Remove the thermostat and inspect | Check if there are dusts or chips in the thermostat valve. Check adherence of the thermostat. | Clean the thermostat valve and reuse the thermostat. Replace the thermostat, if it doesn't work properly. | ||
| Heated excessively | Engine overheated Thermogauge indicates 'HI' | Visually check after removing the radiator cap. | Insufficient coolant or leakage. * Be careful when removing a radiator cap of the overheated vehicle. Check air in cooling system. | After refilling coolant, recheck. Check the cylinder head gaskets for damage and the tightening torque of the mounting bolts. |
| GDS check & Starting engine | Check DTCs Check the fan motor performance as temperature varies. Check if the fan clutch slips. Check the water pump adherence or impeller damaged. | Check the engine coolant sensor, wiring and connectors. Check the fan motor, the relay and the connector. Replace the fan clutch, if it doesn't work properly. Replace the water pump, if it doesn't work properly. | ||
| Immerse the thermostat in boiling water and inspection. | After removing the thermostat, check it works properly. * Check the thermostat opens at the valve opening temperature. | Replace the thermostat, if it doesn't work properly. | ||
COOLING SYSTEM TROUBLESHOOTING CHART
See also:
• AUTOMATIC TRANSAXLE