To finish the thread, yes, it was the freeze plug and Enrique replaced it, the thermostat & radiator cap for less than $250 in labor. I'm very satisfied. Thanks to all.

Richard

__________________
87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)