Sounds like the oil cooler has sprung an internal leak and is allowing
the oil and coolant to mix. Once this happens, the oil/coolant mixture
emulsifies into a thick goo that does not cool the engine at all. Had
the same problem on my Westy, which led to the destruction of the engine
and subsequent transplant.

The cooler is mounted between the engine block and the oil filter, sorta
sandwiched in there. I guess it could also be a bad o-ring seal on the
cooler as well.

> As the engine began to heat up the coolant started
> bucking and spewing from the tank. I then saw a little oil slick in the
> expansion tank .  What does this mean ?
?

--
TomC
tcarrington@relitech.com
http://www.relitech.com/tomc/tomvw.htm
85 Vanagon Crew Cab
82 Vanagon Westy diesel=>gas conversion
65 Notchback