I think it's normal...
When you take a hot engine that is being cooled by fans and moving coolant through the rad and stop cooling it in those ways... it heats up a bit before the lack of explosions inside alows the temp. to fall.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/showpost.php?p=831799&postcount=13
http://www.peachparts.com/shopforum/showpost.php?p=831807&postcount=14