I will measure the concentration of the coolant as suggested. Sometimes it takes awhile for a good suggestion to sink into my head and will let all know.
And it will be a week or so before I pull the rad and flush. My mom's '89 Buick is acting up, I need to get that machine back in-line on a priority basis before again attacking my little MB problem. My dad, who instilled the DIY in me, is now blind, so it's payback time.
So stay tuned, and I will let all know of my progress, but my next post will be at least 1 week from now.
1995 E320 Sold at 288kmiles