Overheating after replacing Thermostat and Water outlet/bleeder valve and bled air from system.

Have you bled the system out there is 1 or 2 spots there are little valves. You will need to run it get hot then open bleeder to let out air. it can be done with it running just watch to engine don't get to hot

one thing that you probably didn't replace is the viscous fan hub
It spins the fan until you need a heavy air flow then it just spins
However if you have then the other thing that causes diesels to overheat is excess fuel
have an accredited diesel shop check the pump and if it is a turbo also have the turbo checked out
have a compression test done to check for head gasket problems.

Continue to add water until the vapor "lock" is purged of all air. All coolant bleeders are supposed to reside higher than the radiator/coolant filling area...the coolant should flow out of the bleeder valve before tightening the bleeder shut.

About the only thing left is the water pump.

Have you checked the fan? A bad fan either electric or manual with clutch will cause a heating problem.

Sounds like you still have air in the system. What engine do you have? There should be a bleeder valve on a housing on the engine where the upper hose attaches.

Fill the reservoir with coolant and open the bleeder valve. Start the engine and let idle. Close the bleeder when a steady stream of coolant comes out. Continue to let the engine idle while periodically opening the bleeder valve to check for air. Keep the coolant level full while the engine is running. Once the fans come on the air should be bled out and the radiator cap can be reinstalled. Snapping the throttle a couple of times will also help push air out of the cooling system.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

For what.

make sure that the system has been bled of all the air to do this there should be a little bleeder screw near the thermostat housing open this up until water comes out start the car and turn the heater on high watch for any air bubbles to come out of the bleeder until it is straight fluid coming out see if this fixes it, also check the radiator cap this could cause overheating too, if this is all fine check the fan switches to make sure they come on at right temperature.

cool air and overheating point to low coolant level. Do you have a bleeder valve near the thermostat? You may have air trapped in the system. If no air trapped, the radiator may be plugged up not allowing proper circulation of coolant.

let me know about the results