So many questioins so little knowledge

Well, I had it at the deal and spent the 100 bucks for them to flush and fill the coolant system. They said it was within the acceptable temperature range to begin with. They did mention that the radiator was slightly clogged and shined a light on it. Even after power washing part of Alaska was still in there. With as many times as I have done this, I did it again. This time I took the radiator completely off and soaked in some acid to clean the fins. After scrubbing with a brush and blowing air thru the fins to knock out some more of Alaska out. I think this time I got it or atleast it aint getting any better.

Kind of hard to tell from blurry picture but the lower third still had a bunch of sand like grit wedged in the fins. The yellow is where you could see thru the fins. From a distance and at angle you couldn't tell how clogged. After taking off and holding up to the sun you could tell. For the most part it looks cleaner than before. Temp is running a little cooler and I'm not messing with it any more.

I was going to suggest replacing the radiator - just checked on Max's fiche and it is typical BMW pricing - $654.00

Since it is out are you planning to use a stiff bristled (plastic) brush to clean out the areas that are clogged.

Would CLR work?

CLR may have worked but I think it would of taken longer. The pink acid stuff I used was for cleaning aluminum air conditioning coils. Really foams ups and eats away everything leaving the aluminum clean. It just couldn't get the sand like grit. I tried to use a pipe cleaner but it was too big to fit in between the fins. I used air pressure blowing from the opposite direction.

I didn't think I needed a new one because really the temp was always in the acceptable range just a little higher then when I bought the bike. Never above half scale and the over temp light never came on. Just me being anal about temp range.

At least now I have the confidence that I was refill the coolant correctly.