Ken wrote: I will say that I am coming to think that the radiator is a much
overlooked
source of badness in the Vanagon cooling system.

I want to post a strong Second to Kens comments on the Vanagon radiator.  I
fought cooling problems in an '85 for years, to the point it cost an
engine.  New engine in, instant overheat.  New radiator, ran perfect.  The
local 'experts' (none on this list) kept telling me "Head gaskets", my
common sense kept saying "Radiator" but I deferred to the 'experts' and it
cost me an engine.  If you Vangon acts like the cooling system just can't
get rid of the heat being generated but all else is well (no leaks, system
bled properly) then replace the radiator!