A wellknown and notorious Z3 bug is a failing fuel meter. (Needle on empty, amber light on while tank is filled)
This can be the result of a dirty or broken ceramic plate located in the fuel sender unit. Under certain circumstances it can be fixed by cleaning the plate, but often it breaks as a result of issues with the tank breathing system creating vacuum in the tank, collapsing the tank and breaking the little ceramic plate. Both tank breather valve and active charcoal filter should be replaced when this happends. On USA, French, German amd Dutch Z3 forums loads of topics on this specific bug. A little less here.
Until now buying a complete new fuel sender unit (pump + level sensor) was the only remedy, cost for the part alone around 300€. For the Dutch Z3 forum we arranged a car electronics factory to make the white ceramic resistor plate only. It was quit a costly , lengthty and complicated process but after some thorough testing and patience we succeeded.
If in the nearby future anyone encounters this problem, you can sent me a PM. It is selling on ebay as well. Costs for the breaking part are only 20€ shipped worldwide. We have some left. Hopefully we can help fellow Z3 drivers with this and compensate the costst and efforts for this project.
