Hi.
Due to my working hours and not being able to find a decent place to do the replacing of the sensor and oil filter on the spot and long waiting hours, I have decided to give it to some mechanic that will, according to him, clean the system, oil pump and all the components and verify if they are damaged plus the pressure test.
It will be done next week and I'll get back with what he found.
Best regards,
Octavian