So I just pulled the cylinder head off the engine to check on some bad cooling issue I've been having (cylinder walls and everything looks really great, some carbon ofc but really okey) and it's pretty clean around the watter jackets too, so the problem has to be deeper in the engine, it has a great telltale but the cooling still seems bad, does anyone know how to best clear out the paths? For now I've sprayed half a can of rust solvent and degreaser in there to see if that does anything but it feels like I need to dig deeper, or do I?