That is one of the freeze plugs but that's the passenger side and no, it's not leaking there. After looking at all the pics again it seems like coolant would be coming from the top center of the engine which is where alot of the coolant hoses are. (and the water pump) If ya had some top pics without all the engine covers on you'd see more. Most all your pics are of under the alternator and most of that fluid looks like power steering fluid. How much coolant do you say is leaking, do you have to fill it every day?