Water Pump: Testing and Inspection

WATER PUMP DIAGNOSIS
A quick test to tell whether or not the pump is working is to see if the heater warms properly. A defective pump will not be able to circulate heated coolant through the long heater hoses. For additional diagnosis, refer to Cooling System; Testing and Inspection. For water pump inspection, refer to Cleaning and Inspection. The water pump on all models can be replaced without discharging the air conditioning system.

NOTE: It is normal for the water pump to weep a small amount of coolant from the weep hole (black stain on water pump body-3.2/3.5L, or at weep passage below the thermostat housing-2.7L). Do not replace the water pump if this condition exists. Replace the water pump only if a heavy deposit or a steady flow of engine coolant is evident on water pump body (3.2/3.5L), or from the weep passage (2.7L). This condition indicates a shaft seal failure. Be sure to perform a thorough analysis before replacing the water pump.