You may be onto something there with the Seafoam, though Seafoam is not necessarily what I would use. Nevertheless, if it works, it works, and as far as I know, Seafoam doesn't harm anything. It's just not the strongest cleaner.
I think you had a sticky lifter that wasn't getting enough oil in it. Probably the one-way ball valve had some varnish or sludge in it or other debris. Most thin ILSAC/GF6A motor oils polymerize easily and leave residue behind when the engine cools down. You basically cleaned your ticking lifter or lifters.
Lubegard Bio-Tech also has a potent anti-oxidant, the same one found in Red Line, called Butanedioic acid (4,5-dihydro-5-thioxo-1,3,4-thiadiazol-2-yl) thio-bis (2- ethylhexyl) ester. That will also clean dirty lifters, but it takes some time. That, along with the other detergents found in Lubegard, is what makes it "magic."
The problem with Lubegard Bio-Tech is that when you use it dilutes the other additives in your motor oil. I only added Lubegard Bio-Tech to ACEA A3/B4 motor oils because they have higher concentrations of everything and are more viscous. After your lifter clean is gone, I recommend you do a flush with Lubegard Engine Flush and use good 0W-40 motor oil. I mean, it's your option if you want to keep using 5W-20 because that will work as well, but a thicker oil will make the engine sound so much nicer, keep it cleaner than any 5W-20 ILSAC oil, and provide more wear protection. The downside? I slight loss in fuel economy.
