Firstly I would like to apologise for no photos. I have had in the past poor idling and misfires when driving causing the car to be virtually undriveable. However I noticed that if I removed the wires going into the back of the valvetronic servo actuator motor that the engine would run much better and almost perfectly. However if I disconnected the leads going in to the eccentric shaft sensor it ran poorly again.
What I deduced from this was that the motor itself was working in that when I pulled the wires out ( and depending where the faulty sensor left the cam position, ie not fully open) the car ran well , however other times when the wires were pulled out and the cam was in the wrong position , ie the faulty sensor moved the cam to a bad position, it was back to running poorly..
Let me say I know I should have used Carly, Impa or some kind of generic code reader but on a limited budget and noting that some peeps had trouble downloading the software (me included) I decided to do the dumb thing and buy a new VDO eccentric shaft sensor off of ebay for around £160..
To access the sensor you have to take off the rocker box cover which was relatively straightforward, the bolts are all clearly visible and have easy access. By taking off the rhs bracing strut allows you to remove the cover more easily.
Once off the eccentric shaft sensor is once again easily accessible. I lightly stuffed clean rags around the sensor down the areas where if I dropped one of the retaining bolts it would not fall into the engine block itself. The three retaining bolts were a bit difficult to remove in that the heads do not protrude out from the sensor very much so great care was taken not to strip the heads. The middle bolt proved the worst meaning I had to grind down a socket to allow it to pass through a hole in the chain tensioner allowing access to the centre bolt.
It was then just a reversal of what I did in the first place to get it back together.
I have read different posts on how to reset your cam sensor/ motor actuator. One said put key to position 2 and pump accelerator 10 times which I did, however on start up it was still very lumpy on idle so I revved the engine ( up to around 3500 rpm ) a few times and as I did so I could here the idle getting better and better as the computer re set the eccentric shaft sensor/ motor into its correct orientation. I take it you guys know the motor has a worm gear on the end of it which moves the cam into differing positions depending....
I straight away noticed a difference in that the idle was much smoother than it ever has been so I took it for a drive.. Wow what a difference, much smoother, more torque and quite a significant improvement on fuel economy.. I was so happy as this has been an on going problem which is finally sorted..
Once again sorry I didn't add photos... I am not a car mechanic by any means and have the basic tools. I wanted to post this as I have read one or two others that have had rough idling and running issues. This solved my problem and I am not suggesting this is yours but it may be. For some reason the 2.0 Z4 seems to have more issues with the sensor and motor than the 3.0 Z4.. The only thought I had on this was whether the 2.0 engine runs hotter causing these parts to fail.. who knows...
What I deduced from this was that the motor itself was working in that when I pulled the wires out ( and depending where the faulty sensor left the cam position, ie not fully open) the car ran well , however other times when the wires were pulled out and the cam was in the wrong position , ie the faulty sensor moved the cam to a bad position, it was back to running poorly..
Let me say I know I should have used Carly, Impa or some kind of generic code reader but on a limited budget and noting that some peeps had trouble downloading the software (me included) I decided to do the dumb thing and buy a new VDO eccentric shaft sensor off of ebay for around £160..
To access the sensor you have to take off the rocker box cover which was relatively straightforward, the bolts are all clearly visible and have easy access. By taking off the rhs bracing strut allows you to remove the cover more easily.
Once off the eccentric shaft sensor is once again easily accessible. I lightly stuffed clean rags around the sensor down the areas where if I dropped one of the retaining bolts it would not fall into the engine block itself. The three retaining bolts were a bit difficult to remove in that the heads do not protrude out from the sensor very much so great care was taken not to strip the heads. The middle bolt proved the worst meaning I had to grind down a socket to allow it to pass through a hole in the chain tensioner allowing access to the centre bolt.
It was then just a reversal of what I did in the first place to get it back together.
I have read different posts on how to reset your cam sensor/ motor actuator. One said put key to position 2 and pump accelerator 10 times which I did, however on start up it was still very lumpy on idle so I revved the engine ( up to around 3500 rpm ) a few times and as I did so I could here the idle getting better and better as the computer re set the eccentric shaft sensor/ motor into its correct orientation. I take it you guys know the motor has a worm gear on the end of it which moves the cam into differing positions depending....
I straight away noticed a difference in that the idle was much smoother than it ever has been so I took it for a drive.. Wow what a difference, much smoother, more torque and quite a significant improvement on fuel economy.. I was so happy as this has been an on going problem which is finally sorted..
Once again sorry I didn't add photos... I am not a car mechanic by any means and have the basic tools. I wanted to post this as I have read one or two others that have had rough idling and running issues. This solved my problem and I am not suggesting this is yours but it may be. For some reason the 2.0 Z4 seems to have more issues with the sensor and motor than the 3.0 Z4.. The only thought I had on this was whether the 2.0 engine runs hotter causing these parts to fail.. who knows...
It will hopefully inspire others who are not mechanically gifted to “ have a go “ I would say however that reading fault codes really ought to be first before resorting to spanners :lol: