CLR is a chemical you can get off the shelf at walmart, it is used to de-calcify stuff. Wear gloves, and don't get it on your clothes.

 

Oh alright will do while I’m at it I’ll back flush the heater core again why not lol

 

Use the chems on the heater core. It'll break crap loose, so you can flush it out.

 

Alright I will do that I just figured with brand new heater core and thermostat idk what could be left to change but it’s probably where the crap is coming off and just re clogging the heater core back up

 

Might want to drain the block to. Usually what I do is add a cleaner then drive 100 miles or so. Drain everything (including the block) then remove the thermostat. Add straight water and another cleaner and take a 20 or so mile drive. Drain and again fill with just water this time. I will keep doing this until it comes out clear. Then when it does back flush the heater core replace the thermostat, fill with 50/50 and you are done .

 

I will definitely try that thank y’all for the suggestions