And just to be certain, are you using the tank that came with the kit or a different one? If the coil, regardless of source, says 0.6 ohm then it's correct. You can buy coils in all sorts of design with resistance quite different from one to another. If however the coil is rated 0.15 ohm and showed 0.6 then it's an issue so rather than assume, just double check the coil for its rating.