kerry holley

we have a 2003 f-250 that has the classic flutter noise in turbo under load. ther are no codes present,and we have replaced the turbo,vgt,and reprogrammed per hotline suggestions.now hotline says to disassemble new turbo and inspect for sticking vanes-turbo has less than 100 miles on it.does anyone have any other ideas or run into the same problem?