A few weeks ago I discovered a coolant leak (was the thermostat gasket). Since the car has over 100,000 on it I decided to replace upper and lower hoses, thermostat, and water pump. Everything from Pepboys. All went well except for installing the idler pulley. I had to grind down some casting marks for the pulley to free spin. Now the car has a "rattling noise to it. I removed the belt today thinking I did not grind down enough on the idler pulley. That was fine. Hand spun the water pump and it has a squeaking noise to it. Sounds like slipping on rubber. Started car for a few second to see if noise still there without belt. No noise. Sprayed WD-40 on water pump shaft and no change to noise. Reinstalled everything and noise is still there. Am ideas? Bad water pump?