engine vibration when stop light

Help needed!
96 saturn ls automatic trans.When the car is in gear vibrates,we check for vaccum leaks .none.new plugs and wires,good compression ,egr valve closes,no check engine light.new idle control.motor mountings new.tps ok. is a fast vibration no like a miss en the engine,feels like a broken fan in early cars
Thanks

check for vacuum leak between #2 and #3 cylinder on intake gasket. gasket may be bad or warped intake. also check to see if you have the current calibration on PCM.