now as to why there is no oil, have you considered the dealership would have drained it out to check on its condition and to see if there were any metal fragments in it which may be causing the problem?

The engine may also be making a different noise now as things have cooled down. Let me use when I dropped a piston from the CVH a few years back.... When warm it was a clatter clatter clatter noise that sounded terminal, but it run reasonably considering what was wrong and managed to get up onto the spec lift under its own steam. 4 hours later, after it had been dragged back home it didnt have enough power in the engine to get off the spec lift, same 1 piston missing, same 1 spark plug mullered but it sounded a LOT worse!

Im normally the sort of person who fights for the consumer, however in this case from what I have read, and I dont know the exact facts but it is one of those where you simply dont have a cat in hells chance of winning, I hope im wrong if you persue it but to me it seams unlikely