The symtoms I had when my heads went were exhaust gases getting into the
coolant and pushing it out of the expansion tank, into the refill tank
(behind lic plate), and out it's vent hole to the ground. While this was
happening the coolant light on the dash was blinking but the temp gauge was
in normal operating temp.

Sean B.
'90 V'gon, "Happy Bus"
http://home.earthlink.net/~vgonman