Recently bought an E50 1997 and had it fully serviced includig ATF fluid and filter change. Since that there is odd vibration felt when engine is running. The engine itself feels to run smoothly ( rechanged the spark plugs with no effect ), but I suspect that the problem comes from the automatic transmission ( turbine wheel ?? ) How can that be ? Has the mechanic done some damage when changing the filter or is it possible that the ATF fluid is of wrong type or the level is incorrect ?