I do not know how to figure out what my 98 ZJ coolant issue is. I had some coolant leaks with minor over heating. Heater core inlet & outlet hoses were extremely hot to the touch. Did not feel like coolant was going through upper radiator hose. Figured it was the thermostat stuck closed. Hell it was rusted closed.
I drained coolant from the whole system (very rusty red coolant) and flushed it with a garden hose sprayer, even the block, till water ran clear. Put in a new thermostat & gasket, new lower radiator hose and new radiator cap. Coolant still does not seem to be circulating. After running for 30 minutes the radiator cap is still cold. Both heater core hoses are hot. Temperature gauge in dash reads right at normal mark 200°F. Heater blows out nice hot air. Motor smells hot though when I turn it off.
When I look in the radiator fill neck the antifreeze looks like rust is floating in it.
I don't know what my next step should be. Any suggestions.

 

Could be the fins on the water pump impeller are near gone or completely gone.

 

water pump failure/ corroded impeller. or blocked radiator. A/ try reverse flushing radiator to force out gunk. B/ remove thermostat and run engine to see if top rad hose gets hot. If still cold = water pump. the impeller is alloy so rusts fast. Next time use proper coolant.