I recently had a confirmed head gasket being complete shit, from a local mechanic. They told me that the engine needs replacing, didn’t even suggest head gasket replacement or any other avenues of repair. Once coolant is in the engine, can’t be flushed or cleaned? I’m really not into getting an entirely new engine and I’m hoping for some kind of fix. Meanwhile, I have my eye on a couple brands of head gasket sealant, bottles of fluid type stuff. Is my engine toast?