BMW Questions? Ask a BMW Repair Expert for Answers.
You need to check the oil pressure at idle with a master gauge.
I know one make of car where we had to rerun the oil pressure wire away from other sources of EMI.
The instrument cluster thought the switch was operated, very sensitive.
It will be quite clear which way to go, after you have checked the pressure.
I fully agree with what you are doing.
I think we both know there is a problem with the engine.
I'd like 20 psi hot idle, 60 psi hot at 2000 rpm.
I'd agree, the engine seems fine.
Could be a poor crimp or female terminal contact in the wiring for the oil pressure sensor.
At this point, I will opt out and get a BMW tech to talk to you.