I have a 2001 E320 that has done 97K miles. It was rear-ended a few months back and was fixed. Everything runs fine. There isn't any significant vibration, and the engine accelerates fine.
However at low speeds or idling the "Check Engine Oil" message is displayed. After that "Engine Oil Level Low, Take to Workshop" message on a red background is displayed. I checked the engine oil level and it is near maximum.
RE: "Check Engine Oil Level" though E320 runs fine?
Yes, it turned out to be the oil sensor. It was replaced and now I don't get the warning anymore. Which is a relief, I was starting to worry about the engine block being cracked etc.