Have a 1987 302 which when moving along mostly at 35 and 55 will nibble back and forth. I would call it a transmission shudder but took it to a tranmission place and they did not think it had anything to do with the trany. If I plug up the vacuum hose going to the EGR the shudder or nibbling is less. AOD or in 3rd gear same result. If I move it to netural when it's nibbling then it stops. I have replaced the o2 sensors and the Air control sensor. I have also replaced the EGR valve and position sensor because the only code that gets displayed is the one that states the EGR valve is not working. There is vacuum pressure going to the valve 5-10 when you rev the engine. Maybe I should take it to another trans shop to get a second opinion?

 

Whats is a "nibble"????, I've been wrenching a long time....never heard of anything but people and animals "nibbling".........did'nt know cars or engines could do this????
shudder...yes...nibble...no
However, shuddering or vibrations at certian speeds - could be drive shaft or U joints....bent,bad or mutalated, or maybe a tire "hopping"....out of balance? or bad shocks?...allignment? or
ALL of the above

if we did'nt laugh,....we'd cry....

zipzooom