Old update: I replaced the last couple of coil packs the vibration is gone.
If you replace one you need to replace the rest soon after. You replace all the spark plugs at one time, but you don't replace all the coil packs, why?
The engine did get warm once in the dead of summer, like 100degrees outside. I burped the new radiator and good to go. I think it's a computer issue. The old coil pack fails and triggers it. VSC comes on bc of vibration. Glad that works. Check engine comes on bc of misfire. The other old coil packs don't perform as efficient which computer tracks & flags the issue.
From all the head gasket stories and experienced mechanics tell me that if it's a head gasket issue you'll know it bc it will get bad quick.
It seems more likely a cheaper cost component faulting; radiators crack possibly due to being dirty, so dont drive in the mud lol. Anyhow mine has 260,000miles, 14yrs old, and the problem (not dead on road problem) started 5yrs ago - gone now. It is likely the head gasket repairs for others were warranted, different situations maybe.
I'm sure someone will have a negative comment but I'm not the one messing with the head gasket.
