Bought a new motor as got told car needed one at 330000kms so got second hand one through reputable dealer $1700 motor done 124000kms. April 2012 now car doing same thing it was before I replaced the motor. Powertrain warning flashing, car rocking/shaking and tapping/knocking sound getting louder? Took it back to the 'reputable dealer' they said 'at first' no.3 coil showing on their machine? but didn't replace have asked me to book in next week? Can I replace this 'no.3 coil' myself? something about a engine driver also that may be problem or fuel injectors? Not cover under the motor warranty I'm told??