Help with metallic noise E53 3.0 6 speed manual

[trhaverstock]

My 2004 X5 3.0i is a 6 speed manual trans and has been making a weird metallic rubbing/grinding noise under load. A metal on metal rubbing kind of noise. It is neither really quiet or loud of a volume. I love my X5 but the noise has gotten slightly worse over the past several months and is driving me nuts.

It only makes the noise when accelerating under moderate load but usually not light or heavy load. Has to be in gear to make the noise happen. When coasting in gear or in neutral no noise. Braking does not cause the noise. I replaced my belts and all pulleys except the hydraulic pulley/tensioner (that is enroute right now) and the noise was unaffected. I had my son drive it tonight with the hood up :-) :-) and me hanging off the engine bay. It is coming from the driver side of the engine bay OR underneath with the sound transferring up into the driver side. I also jacked the car up on 4 jackstands and drove it. No noise!! :-) It is solely load based.

I am absolutely perplexed! Any suggestions from the wisdom of the group? I tried to search old posts and saw many things but not any that I felt matched up to these symptoms. Thank you!!! Todd