2004 BMW 325 - Oil pressure light

2004 325i with 128k miles. The engine oil pressure lite is illuminates after the vehicle has not been driven in several weeks. I have has the oil pressure sensor replace and oil is in the crankcase. I have recently had the brakes and tires replaced. Can I change the viscosity of the oil to stop this problem? I would like to drive this vehicle another year.

Did anyone check the actual oil pressure the car generates with a mechanical gauge? If the engine is not producing enough oil pressure, its life is going to be very short.

Find and fix the problem rather than trying to band-aid it with thicker oil. Go back to your mechanic and tell them this problem and get a proper diagnosis. Right now you are totally in the dark.