New poster! (less than 10 posts)
Hi i dont know nothing about these engines at all so just a suggestion
what are the water pumps like on these? are they a plastic impeller on a metal shaft? basically one of my transits did something similar it turned out to be the impeller slipping on the shaft, it would get quite hot then cool rapidly then hot again
the pump wasnt producing enough flow engine got hot stat open and all the cold stuff would mix shut the stat and get too hot again
as well as lots of other strange symptoms, sometimes mostly whilst trying to get it diagnosed the van would be ok so the impeller must have gripped sometimes and slipped others etc! as i say i dont know nuffin about them just a thought