flickering xenon

[domsz4]

ive had a bit of a read around and i think its the balasts?

what I'm experiencing is my lights appear to be flickering but is not they are going on and off so light dark light dark light dark... more like the whole unit is loose and wobbling. e.g driving behind a white van so you can clearly see the pattern and it bounces up and down. Given the crappy state of the rd i thought loose light! but it seemed to happen after halting at lights too. almost like there is a spring in the self levelling mechanism that's worn out .... any thought?

[srhutch]

First suggestion it to swap the ballasts or bulbs round to see if the problem moves. doing that you should be able to work out where the problem is.

[rally-chris]

If it is both lights bouncing then it could be an issue with the levelling system, like the level sensor arm is disconnected from the suspension arm (there's one on the front and one on the back suspension). If it is just one headlight moving, then a common issue in BMW headlights is that the height adjusting motor comes un clipped from the inner light housing that mounts the light units. In that case the motor still works to push the light beam up to a set position when you turn the lights on, but then the light is free to literally bounce up and away from the motor/actuator arm over bumps.

I had this on my previous E91, probably as a result of a light bump on the front corner by the previous owner. The light had been re-adjusted to put the beam in the right place but the actuator ball joint was disconnected and the light used to bounce up and down as I drove along. I think Z4 headlights should be much easier to access the motor and see if this is the problem as they have the single large cover on the back.

Alternatively one of the internal mounting points on the inner light frame / reflector could be broken - I think someone else on the forum reported this issue last week and was looking for a smashed headlamp as a donor to take the reflector out.

Chris

[domsz4]

cheers ill have a look when I can get to it