It sounds different than a Rod bearing knock. First of all it wasn't that loud lol. Doesn't sound healthy thats for sure. What Mike was saying moving your head around the engine bay works for me. To really hear where the sound is coming from, cup one of your ears and use that ear to pin point the noise. Or if you have a really long extention you can use that as a Stethoscope. Put one side of it to the engine, and the other to your ear, this always works for me. Anyway, good luck with the problem. Are you sure you didn't stop anything in the engine? haha.