Knocking Noise Coming From Motor

[chadimus06]

ok recently my 92 sc300 started making a faint knocking noise from under the hood. today its gotten louder. at first i thought it was a rod or main bearing or something. but when i start the car it wont make the noise until it gets to running temp and only at idle. when i give it a lil gas the noise goes completely away. then it'll idle back down and start knocking extremely bad.it hasnt lost any power whats so ever. drives fine. the noise sounds like its coming from the internals but dont know what it could be. any help would be much appreciated.