Engine knock/rattle vs. fuel injectors??? Any help?, Video and description... Options

[celicakitten]

So I've had my car for three months now and still cannot figure out what this noise is! I'm by no means a mechanic but have common sense around cars, celicas inparticular. It's a mostly stock 7a-fe with 194k and 5 spd tranny. The car runs fine, and since I've had her changed the oil, spark plugs/wires, exhaust manifold/down pipe(original was cracked), and have had no other problems...not even a check engine light. I can't find anything loose that would rattle, but there is a significant power steering fluid leak.

http://youtu.be/FOrH0HC7l5w

Please see the video I put on youtube to hear the noise, which is most notable on a cold start and anytime I'm constantly holding revs over 2500rpms, but will stop if I floor the gas or let off it completely...It's very annoying on the freeway(but isn't noticable with the radio on! ha!). I'm thinking maybe a bad piston ring, or possibly something in the fuel injectors??? I should also say the noise does seem to emit from the passanger side of the engine bay. I'm worried it may be time for a rebuild as I do not know how the previous owners treated her. If that is the case my biggest challenge would be finding someone I trust to do the work, but I'm sure you guys can help point me in the right direction for that!

[Smaay]

^^^ if its tapping now, it might be salvageable, dont run it till it siezes up like celicakitten did. pull the engine now, tear it down and inspect it. im willing to bet the bearings look just like the ones i posted.