So I know that a common problem on these OHC 4.0 engines is the thermostat housing will crack or leak coolant. Now looking under the hood, the assembly looks dry but what I AM seeing is the sensors are wet and corrosion is around where the sensors screw or plug into the housing.

Is it possible that it could just be the sensors that need replacement and not the whole assembly? I'm trying to avoid having to get into a costly repair since I know labor costs can shank your wallet hard. It's beginning to get where it will leave wet spots under the truck where the coolant has trickled down to the A-arm and drips off of it. I also had to fill up my overflow tank yesterday so it is leaking, I just don't know if and when it'll get worse. TIA!