The ATF method is scary cuz ATF doesn't have enough film strength or viscosity to prevent metal to metal engine wear. Seafoam contents is 50% pale oil (lube) 30% Naphtha (mild cleaning solution) and 20% Isopropyl alcohol (removes water) So I'm not so sure why its used as an engine cleaner. Maybe a good thing for the gas in my snowblower, lawnmower, or a boat. Something without a cat. MMo is similar to seafoam, but it doesn't have the IPA. It also has a fresh wintergreen smell lol. If MMO is "working" in the engine quieting ticks, that tells you it could be a flow issue. Because MMO thins the oil. But, like Seafoam, it uses Naphtha as the cleaning solution, which is very mild. Going thicker will lessen oil consumption but make ticks worse. Because thicker oil = Less flow. Thats potentially the problem. Flow.
Are the lifters loose? maybe.
Did you lose an exhaust manifold bolt? Maybe. I did.
Go ahead with your syn oil change for a few changes. See if it gets better. What brand?
I am missing manifold bolts but my mechanic told me this was definitely a lifter. Where do I get MMO?