Okay, I located where the sound is coming from. It is coming from this sensor that is on top of the crankshaft near the damper. The sound makes it seem like some metal rubbing with each other. When I pull the wire up, the sound is gone.

What does this sensor do and is it necessary to replace the plate that this sensor bolts on to and also the sensor? And, where does the other end of this sensor goes to?

Do I have to remove the radiator in order to change this sensor? If so... I have to remove the radiator for the third time and 3 quarts of Zerex down the drain! =(