what does the expression "runs on an oily rag" mean?

Question

"if it was a car you would say it runs on an oily rag..."
is that a good or a bad thing?

Answer 1

It means that to keep it running at all, somebody has to pretty much stay under the hood, and poke about with their tools and oily rags... or to keep it working, they have to tie a rag around some spot where oil leaks.

Bad thing=high maintenance, and low efficiency.