wrx2015

hey guys i have a 02 subaru impreza wrx 2l turbo and im getting a heavy misfire and blue smoke when i rev it. Also getting a whistle from the turbo when i drive it could this mean the turbo is on its way out and that would cause a misfire ? i have also changed the plugs and checked for a spark and all 4 coils are working took out the intercooler and they was a little bit of oil around where it goes into the turbo thanks hope someone can help