Oil leak...sensor on Rocker Cover....DIY guidance required

Hi Guys

I need DIY guidance on my oli leak on a BMW 118i, E87, 02/2005.

I have a oil leak from a sensor on the rocker cover located next to the oil lid.

I have tried to unscrew/ tighten the hex bolt (07 11 9 904 527) ....which feels free and does not unscrew nor tightens.... (see attachment)

see link below to see what parts i mean (Parts 7 & 8)

http://bmwfans.info/parts/catalog/E8...er_head_cover/

Any thought how i could un screw ...worried if there is a nut underneath which may fall in the head.....but the nut is not mentioned on the diagram so unsure if there is a nut underneath or not ......

Once I open ...is there a seal that can be changed to stop oil leak....

What sensor is this at the top.......can u please identiy the slide (browse to) on the above link and send the link where sensor is mentioned...

not nice....car parked ...not driving....

tim@oz

where are you

If you are not sure bring it to independent bmw service for $50 of labour

HI

Progress

The nuts are embeded in the Rocker cover....which are fused but the fusing become loose and they were moving freely......was able to just lift the sensor cover with plyers and unplug........need to glue the nuts with super adhesive to make them stick....before i can screw them.....poor quality construction.......

unusual place to have a leak....

all good

Hello
My 120i has just developed the same oil leak as you have described.
What did you have to replace to stop the leak?
Did you need to remove the valve/rocker cover?
Thanks In advance.