[rick bell]

ever stand in line with someone to close to you in the behind position and feel little bumps? the last two flight at low power setting (mp25,rpm24) at 5000k indicating 140 (cruise descent for landing)the feeling starts. no indication on any guage, just the constant little pushing from behind. cobb up to 170-160 indicated and it goes away. anyone have any suggestion what to look for or what is causing it. gear doors up, recycled cowls numerous times, there is no indications on flight controlls (like when bolts on control surfaces get slightly grooved). this takes the fun out
flying and would like to solve it. rick