Hello,

(re.: a '90 745t with 220k...)

The fog that blows out of my vents when I turn on the defrost starting a few days ago covers the windshield with an impenetrable mist that dried to some clear drops of moisture on a very warm day. It's a dry, cool, acrid fog, though--not the "sweet, sticky" stuff I'd expect from a heater core leak. My heat has, though, for the last few months, pumped that sweet smell into the cabin, so the heater core is suspect (to me), but if this fog is a symptom of that, why does it only happen when defrost is selected?

I did tighten the belt on the A/C compressor recently, and charged the system last fall, in anticipation of needing good defrost. The compressor doesn't cycle on reliably--it seems to need *just right* belt tension, and sounds like a sick duck...I assume it's pretty worked over. Also, it has developed its own coating of moisture in the last couple days.

I could live without A/C, but I do miss being able to see out the windshield. Any ideas where my trouble may lay? Or, troubles?

Thanks, Nick