What does thin oil do?
 

one result of leaking fuel into the combustion chamber ( lockup) can be a bent connecting rod when that piston comes up on compression... I have heard of this more than once on this 5.4 motor. Pulling the pan for additional inspection would be a good idea.

Engine is toast. It has happened enough times to know that. The 2005 trucks had the issue on certain build dates. Ford actually provided a 11 year 120k warranty against the damage under program 07M08. Time for you to start engine shopping unfortunately.

Yup this royally sucks. In my other post when this all started "2005 F-150 5.4L Locking up when cranking, Smoking & Mis-firing", 70F100longbed said it was possible to replace a bent rod without pulling the engine. but first, I have to get this stupid oil pan off....What a nightmare. After I get this off, I am sorry to be so ignorant, but what should I be looking for? Is it obvious? Can I tell right-a-way?. Seriously moping in VA. Anyone please help!

You are not going to be able to do much. The bent rod with the noise you have its already done. Start looking for drop in low mile engines. They are plentiful and cheap! Car-part.com

You will have to loosen the steering gear, lower the front diff if its 4x4, and remove the small crossmember under the engine to get the pan off. The fuel dilutes the oil making it thin which can damage the bearings. Its pretty tight pulling the passenger side head with the engine in the truck. You could cut open the oil filter and look for bearing material, it will look like glitter. If that's found, then the engine is done. I wouldn't put a used engine in you never know what you are getting it may have the same problem as your or bad guides, phasers, roller followers, or whatever. If you like the truck get a good reman put in. Ford's remans are backed by a 3 year unlimited mileage warranty.