hi qtiger.

c'mon bro; five radiators and two head gaskets? of course the radiator cap has been replaced. and even upgraded.

drove about 20 miles over the weekend in two trips. coolant leaks from the cap, squeezing out about a teaspoon as the engine cools down.

i'll try your second suggestion this afternoon when i get back to the train station.

how about digging beyond the obvious, y'all. what could be happening in this engine to create a blockage - if that's what it is. or what about the possiblity of a crack in the engine block?

i'm depending on you cats to gimmie some sort of clue.

many thanks!!!!!!!!