2007 BMW 630i with N52 engine - Defective Valvetronic system

[mar64]

Hi, I'm currently experiencing a problem with the Valvetronic system on my BMW with N52 engine and it would be great if I could get some advice.

As the diagnostic suggests it relates to a potential defective Valvetronic system. I've removed the valve cover to inspect the Valvetronic system/eccentric shaft to see what was happening. So far, I've bench tested the Valvetronic motor and put DC current from a battery to it and the motor seems to be working as it should. With an allen key I've also manually turned the motor onto the eccentric shaft to see if there is any unnecessary resistance in the shaft and whilst of course the shaft is under spring loaded tension it does appear to be ok.

However one issue I have noticed is that the motor does not seem to calibrate. I put the Valvetronic motor back in its position on the car - connected it electrically - and connected the eccentric shaft sensor. I then turned the ignition onto the second stage in an attempt to calibrate the motor - I understand this can be done from the second stage of the ignition, also I don't have software - and the motor does move and position itself onto the shaft. However it doesn't move any further and certainly doesn't seem to calibrate. My understanding is that the calibration should allow the Valvetronic motor to run through its min and max positions and it's clearly not doing this.

So I was wondering if you could confirm whether it's possible to calibrate from the second stage of the ignition and from the first clip if the motor is calibrating or not? Also do you think the defective Valvetronic system issue that I have could be caused by a defective motor or feed to the motor? Also any advice or suggestions would be a great help.