g'day montanagold you say you are running the same settings as the nuggetfinder and the second hand coiltek coil is noisy i would say it could be the coil the only way to fix this problem in the future is to buy new for the $$$$ you saved on the used coil that may not come with a warranty so now you have to pay for it to be repaired or purchase a new one ps try your mates coil and then you will know if your coil is faulty