M3 E46. Oil leak / Origin?

  • Hi All!

    For the last 2-3 years we have an oil leak somewhere under the hood that drops into the botton plastic protector, even through the sway bar. This leaking only happens when a reasonable number of kilometers are driven. Not when 5-10km.

    We firstly replaced the top gasket in the motor and the top part of the motor is dry since then. However, oil keps dropping. We replaced a bolt in the back side of the motor that seems useless (kinda as to cover a casting hole or similar), and the backside of the motor never was humid again.
    Since the oil pan was really wet, the next to be replaced (in last Christmas indeed) was the related gasket. But we kept having oil in the lowest corner of the oil pan to motor connection edge. So we added some silicone to that corner to grant (or try to grant) this would not leak. But the oil dropping persists... and such an oilpan-motor edge is still wet over the silicone.

    The vanos lower area seems to be dry (dirty though). So we wonder if the problem could still be the oil pan gasket, or maybe the cylinder head gasket?
    We cleaned the dirt with brake clener, but it is not possible to remove it all without disassembling many parts.
    I provide some pictures in case these help (the silicone CAN be appreciated in one of them).

    Any suggestion on how to identify the origin of the leak? Where this may come from?
    Thanks a lot!