I just installeld a Goodman 1.5 ton split... pressures are fine but the evap coil is making a heck of a racket. It is definitely refrigerant noise, because it doesn't happen with just the furnace fan running. Its an uncased A coil, and I didn't mess with the metering piston because it's a matched system. I'm waiting to hear from Goodman, so if anyone has had this experience please give me your comments. This is a new one for me.