Hi G first of all don,t drive the van anymore sounds very like head gasket but unusual at 56,000. I had same problem with 01 2.4 transit last year, some of the lads were driving it on the motorway and it stopped when we got it back to yard found same problem. Head gasket was really blown hardly any compression in cylinders it was all going to exspansion bottle thus it would have blown your hand off to take the cap off. We parked ours up as it had 160,000 and really wasnt worth fixing. A couple of months later some guy came and asked to buy it so the boss sold it to him, he came back later and told me that he had to replace the whole engine as it was totally fried so dont drive yours if its overheating cause it could wreck it altogether
Kev
January 2009