This is called the creature. The problem was some times it is hard to find things in engines that go wrong.
This creature will crawl in and tell you what is wrong and then fix it. It fixes it through nano technology that is dropped on the broken part. It could be a ceased bearing and the nano technology will place anti corrosion material on the part to get it going again.
It is intuitive, the creature will go where there is a loss of volume, pressure or increased friction. It will save a lot of loss time and human intervention.