Big thanks to szatyo for sharing this experience. My Mother-in-law had exactly the same symptoms after taking her 2012 Roomster for a simple oil change service. The gob****es at the local garage replaced the oil pump, oil pump chain, and oil pressure sensor trying to hunt down the issue....and presented her with a bill of more than £700. Then they told her that this engine only has an expected life of 80,000 KM - and she needed a replacement.
After 15 mins. of Google searching I found this post. Went up to the old folks place at the weekend...removed the oil filter...and there, clear as day, was the old o-ring. It took me literally 10 minutes to fix the issue. Massive brownie points earned, smiles all around.
Winner!!
