wierd rattling/grinding sound.

[ImPLiCiTS14]

Today i was driving on the highway on the way to work and out of nowhere the car starts making a grinding/rattling sound. I notice if i give slightly more gas it seems to quiet down but if i let the car decelerate it gets loud.When i press the clutch pedal i feel the grinding/rattling. Almost like rod knock there is no lack of power or anything.
all of this is in a 95 240sx.
any help would be appreciated.

[jodett]

does the noise go away when the clutch pedal is applied? I know you said you can feel it, but if it goes away when the clutch is down it is probably your release bearing.

[ImPLiCiTS14]

I have a sound clip but dont know how to out it on her.

[FRoSt415]

I have a sound clip but dont know how to out it on her.

upload on photoucket or youtube or any video hosting site and past the link here as you would do for a picture and done.