i run you finger around the bottom of the bell housing where the SD meets your engine
there is some leak around the seal.
but sometime a found clean oil , on my diaphragm !!! this i realy do not understand
i have remouved the sensor, no oil found between the two diaphragm, as far i can go with my tiny tube, but the main leak is at the oposite at the sensor !!, i didn't went as far
but for sure a had oil in it there: the sensor was durty by oil (used one)
i have cleaned again, to see if oil leaking again (four time now,once every two day)
i have to clean the sensor now,and check it