The other day on the highway I heard a clacking each time I used the accelerator that would stop if I let off the gas. Eventually the sound increased in volume until the engine would not respond to the pedal, and shut off. It seemed to have overheated, partially due to the radiator leaking.

A half an hour later and some fresh water in the radiator and the LTD fired back up and made it home, but needed extra gas to stay up at a normal idle rate while in gear. Eventually over the next few days the power completely died out of the accelerator, and will now will not fire up. The last few starts it would fire up in park, then die when shifted into drive or reverse.

I know I should fix the radiator but beyond that something else is stopping the car from driving at all. The first guy said clean or replace spark plugs (cheap and quick), second said fuel pump or filter (I have no idea where I would locate these), and then my brother said maybe a head gasket is blown (might be totaled). The air and oil filters are new - Thoughts? Questions? Please be as specific as possible because although I have a basic understanding I don't know much about engine work, and want to save this car on my own if possible.

 

I think the sounds you heard were those of pre-ignition/ detonation. They sound the same , but are different. They also cause the same result when caused by engine overheating. Unfortunately , I think, you have some burned valves and possibly a head gasket job on your hands. How do I know? Because I did the same thing once many years ago when I could not see the darn red overheat lite because the steering wheel was in the way. My problem was caused by a thermostat that stuck closed, but the result was the same. Lets hope you get away with a cheaper solution.