While at the ramp today trying to put some hours on the new motor, kept hearing this noise.......sounded like a High Pressure "PSSSST"/or like a high pressure pop off everytime #3 fired. Pulled the cowl and fired it up again and saw puffs of smoke everytime I heard that "PSSSST" sound. Shut it down and looked around and found #3 bleed line burnt with a hole in it in the middle of the bend about 1 1/2" off the nipple in the block. It's definetly a burn through the line. I'm open for ideas because I'm somewhat clueless, it's not from contact with anything else and there's no sign of wear on the OD of the tube.