hi
sounds like your engine is stuck in timing setup mode.
i had this pain in the ass problem! easy fix and very cheap.
if you ever tried to set the timing up on your G60, you will no that you have to disconnect the BLUE water sensor on the top front of the engine so the engine can be changed into timing mode.
here's a way to test it.
start your G60 and pull the BLUE water sensor connection off. if the sensor is ok it will start running badly, so you need to put it back on, but if there's no change your sensor has had it and you need to replace it.
easy.
hope this helps
