What harmonic balancer is on the motor? A/C car? Pulling the belts off would eliminate the alternator & water pump. I'll assume you've already checked the fan & pulley for any wobble. Does it sound like a bad bearing, or a rhythmic ticking, or contact between a rotating item and pan or tray? Definitely from the front? Does it change with clutch pushed in? Might want to pull valve covers & poke around, though you said "middle front".
