I'm prepared for a head job on this car. Once the cheap stuff was done, i.e. verifying engine fan, flushing system, changing t-stat, was done and the problem did not go away and seeing brown sewage lining the upper radiator connection to the block I thought the radiator might be plugged up. I noticed that it was not an even temperature, asked a mechanic for his opinion and he agreed that it was not in great condition. I didn't think the rad would solve 100% of my problem, but believed it was part of the problem and neede to be done AND the A/C condensor needs to be replaced, which requires moving/touching the radiator anyway.
Since I've never had a cooling system get plugged up before, I'm wondering if deposits are causing the slightly higher temperatures? The flushes I ran thru the system seemed to "loosen up" the deposits, but did not comletely remove them.
I see NO oil in the coolant and no coolant in the oil. The turbo boost sense line was cleared maybe 45000 miles ago before I purchased the car. And I'm pretty sure the coolant temp has run about the same (actually, its SERVERAL degrees lower than before my first coolant flush in Junuary) since I purchased the car, about 33000 miles ago.
The chemistry of distilled water is such that it attracts metals since its so pure. Regular tap water has a small % of stuff in it that keeps it happy. Antrifreeze + distilled water is a happy combination.