The engine needs a head gasket replaced.

“Selling a nice project car to make way for another. It’s a rare 1951 Willys Jeepster that is reported to be one of the last off the assembly line. It has a 6 cylinder f-head 161 cubic inch engine in it that runs but needs work (head gasket). Also has an overdrive transmission for good fuel economy. Odometer shows 80K miles. Has radio and heater … The Jeepster is in overall good condition. I bought it a few years ago from a fellow in West Virginia with the intent to restore to original. Another car’s caught my eye so this has to go … The front floors have been patched, the rears are good as-is. The body has minor rust but is very workable. The frame and suspension are in great shape with just the average surface scale. All lights work.”

http://cleveland.craigslist.org/cto/1772277592.html