C30 oil pressure warning and engine noise

Low oil pressure and engine noise are definitely not good signs. Did you notice any oil leaks? I had a similar problem with my old Opel Astra, though the symptoms were slightly different. Turned out the oil pump was failing, starving the engine of oil. But loud mechanical noises, especially with low oil pressure, can also point to damaged engine bearings. Have you checked the oil pressure gauge to verify?

No visible oil leaks that I can see, and I don't have an oil pressure gauge installed. But now that you mention it, engine bearings sound expensive! Was your Opel making similar noises before the oil pump went completely? Anything else I should be looking for?

Yeah, the Opel started with a subtle ticking that got progressively worse. Eventually, the oil pressure light flickered on and off, then stayed on. Given your symptoms, and the lack of leaks, I'd say get it to a workshop ASAP. Continuing to drive it could seriously damage the engine, if it isn't already.

Thanks for the advice! Ended up taking it to the shop, and you were spot on. The oil pump was kaput. They replaced it, but sadly, the low oil pressure had already damaged the engine bearings. Total repair cost me 755€... Ouch!