Going to try BlueDevil Head gasket sealant, your tips/advice

Blue Devil (and another product) have allowed me to get from 195K miles to 245K miles on the 5.4L engine in my wife’s Ford Excursion. It is not a permanent fix as I’ve retreated once in this interval (just recently). The vehicle has always had some coolant loss, but it maintains the pressurized hot tank level better now than it did at 50K miles, so my experience with the product has been positive. Be sure to follow the directions as it is not just “pour and drive” as the car should be allowed to cool off after the initial treatment.