Mercedes B Klasse Hybrid Oil Pressure Issue

That sounds familiar. I have a B Klasse too. Had a similar problem a while back: oil pressure light. Did you check for oil leakage before thinking it's the oil pump? And after the oil change, is the oil level correct? Did you use genuine Mercedes engine oil? It could be something simple, or maybe not...

I inspected the engine bay for oil leakage, but found none. The engine oil level is within range. I didn't use genuine Mercedes engine oil, but a high-quality synthetic oil that meets Mercedes specifications. Could the non-genuine engine oil be a factor, or is oil pump failure more likely?

No oil leakage and the oil level is fine. Generic oil shouldn't cause it that fast, but who knows? I'm leaning towards oil pump failure, especially with those noises. I'd get it to a workshop ASAP. If it is the oil pump and it fails completely, you're looking at serious engine damage. It's not worth the risk.

I took the car to a mechanic. They confirmed the oil pump was defective and needed replacement. The repair cost was 755€ Thank you again for your help.