Even though I couldn't see water flowing in the top of the radiator - even at higher rpm, plenty of water chugged out of the upper hose when removed from the radiator.
The radiator drained as this weentr on I presume due to the action of the water pump. Can a water pump be only working at partial capacity?
I can’t get my head around around what would cause the symptom you’re describing in the first paragraph. I’m not doubting that you observed what you observed, it’s just weird.
I would think you could do the combustion gas test at Mom’s house without many tools. Perhaps that’s a place to start.
