hi all
A friend of mine had the same problem. Oil pressure light was on and in the end we needed to replace the engine because the crankshaft bearings were gone because the oil pressure was too low. The problem started after he changed oil. Because he bought the car and it was long ago that the car had an oil change.
I removed the oil pump. The pump itself was good but the problem was the Oil pressure valve. ( überdruck Ventil mit Teilnummer -15131, -15132, -15133,-15134,)
It was stuck in the oil pump case and i needed to get an hammer to get it out.
Das Uberdruck ventil needs to open and close smooth. This part is needed to get more and less oil pressure. It should open and close easely.
This is why it is so important to change oil every year or every 15000 km.
The car from the friend of mine didnt have an oil change in the past 4 years and now the Oil pressure valve was stuck in the case.