Not mine, but a friend of mine....

His 1979 240D was making a 'funny noise' and I dropped by to see it. I raised the hood and there was oil everywhere. It did start and knocked real loud. It also blew oil out of the dipstick hole.

Bottom line.... The bolt holding the dipstick tube had come loose and allowed the tube to come out. Then oil was ejected through the hole in the block until there was almost none left.

And then.... The death rattle.