A neighbour with a Zaf.B diesel, was told (during his MoT) that he had an oil leak from a sensor on the back of the sump, he decides to investigate and tries to pull out the sensor, breaking it. It was the oil level sensor and is fitted from inside the sump, several days later and a few hundred quid it is going back together. An ansolute bugger of a job, especially as he is working on the floor in the rain.
Moral: if in doubt look up how to do it online BEFORE getting the mole grips out.