I am surprised that the shop didn't advise you to replace the thermostat since they are already working on the water (really close to one another).
To answer your question, faulty thermostat does not control the operations of the water pump. For as long as the engine is running and the serpentine belt is attached, the water pump will continue running and will not circulate the coolant kin the thermostat is stuck closed.
There are several reasons why a vehicle overheats.
1. Faulty thermostat.
2. Faulty coolant temp sensor.
3. Radiator fans not working.
Answer these questions.
Does it overheat all the time, or some of the times? If so when? At idle, at the stop light, while you are driving. What speed.
What you notice it overheating, do the radiator fans turn on? Do you have enough coolant? If you turn the fan control to maximum and temp control (on the dash) to full heat, does that help lower the engine temp gauge in the instrument cluster?
Sunday, March 15th, 2009 AT 2:34 AM