stalling out and knocking noise

[00 challenger]

I just purchased a 2000 challenger and i went out for the first time and it ran fine for half an hour or so then it randomly cut out and started progressively getting loud with a knocking noise. does anyone have an ideas?

 

[Dr Honda]

A knocking sound while at idle is your jet pump... but what you are describing is something bad in the engine.

I would start by making sure the motor mounts are good. Grab the engine and try to rock it back and forth.

Also, check the compression, and let us know what your spark plugs look like.