How do I know if my waterpump is truly not working. I have 2 for my 4A-GE, and a new one is like $69.00 from CT. The inner fan, turns good, and coincides with the rotation of the pully. No berring noise, and not much play in the shaft. Do I really need to change it? I mean money is money, and I have other uses for it. Maybe I'm just overheating due to a thermostat? Also, I replaced the waterpump gasket (after doing timing belt) and now temp-sender is not working. Do they go often, I mean is that somthing that breaks a lot on this car?