Thread: Possible misfire, plus whining noise?

2002 crown victoria 213k miles

at 45 mph or 3rd gear approx car starts to shudder consistent with pedal pressure (less = more shudder) there is also a whining whirring noise (not bearings all been replaced) that seems to be made worse by acceralting but remains during coast. When I put in in neutral it goes away. I get that the shuddering could be misfire or speed sensor, but if in "N" does the pinion bearing cease to spin? if it does I am out of ideas if it doesnt i think that could be it. Not sure if it is loose will check that on lift this week. No rear diff fluid leak (new lucas put in when bearings swapped). Ujoints tight

i agree with the speed sensor and the i would spin the tires on a balancer and see if their is irregular wear

sounds like the torque convertor they do that when starving for fluid. has the transmission been serviced