Please help Engine Noise

[rob_4187]

Yesterday driving home from work i heard a noise that sounded like my pcv valve was letting out alot of air when i reached mid and high rpm's. When i let of there was a whooshing sound that kinda sounded like an extended blow off valve (which was kinda cool at the moment). I drove about 5 more miles and i noticed the lower my rpm's the louder the noise until eventually i was idling and it was a horrible clanging noise. I pulled over and the sound was unbearable so i turned it off and got it towed home. It sounded like i had thrown a rod. I was wondering if there may be a different problem. The sound is coming from the center of the engine. I read earlier about people who had similar symptoms and it was either a sticky valve or a plate (cant think of it right now). Any way to diagnose it from my driveway? Also wouldnt a thrown rod mean engine rebuild? Any approx. costs on that? Thanks