have a coolant leak. and for some reason believe its the block
I would figure out where it’s leaking and repair it. If you don’t have access to the tools to do it yourself, a well recommended independent mechanic would be the best way to go. Definitely no need to go to the dealership
If you have difficulty finding the coolant leak, there are dye kits you can purchase to add to the cooling system, then you inspect the engine under UV light to easily find the source of the leak. Coolant leaks I wouldn’t normally think of the block as the first culprit. Usually it is a rubber hose, its connection to the block, the radiator, or the water pump that’s doing the leaking. If it is the block, cross your fingers it is a core plug, and those are usually pretty simple to replace. Coolant gets acidic over time, so keep up w/the routine maintenance by replacing the coolant per the manual intervals.