Well, I rolled the dice and put a bottle of Blue Devil White Label Pour-N-Go Head Gasket Sealer in this afternoon. Followed the directions to the letter, actually took more like three minutes vs. one to slowly empty the bottle contents into the radiator, gave it an additional half hour or so at idle beyond the recommended 50 minutes. No indications of any heater core or rad clogging, all temperatures totally normal during the post fill idle session and a later (after letting things cool off and topping off the system) half hour test run on I-95, including a "hot soak" after a high speed run on the interstate going through a drive in at the Dunky's in Mystic. Ran in A/C mode during the post fill extended idle, the fans cycled between 185 and 175, maybe a 50% on duty cycle. Ran with the A/C off on the test drive, again, all temps totally stable and normal. One thing I have noticed is that the rad hoses are a LOT firmer now after the treatment, more like I would expect from a tight system than I have been observing lately. Also don't smell any significant amount of coolant in the engine bay like I have been noticing of late. Keeping my fingers crossed that the fix has actually "taken" and holds.
