Can't find a previous post of a water leak issue (they wondered if it was HGF) suggestion was mad re the water rail leaking and running towards the front of the engine block. They asked for a photo of where the rail fixes to the head.
Anyway, I've attached 2 photos (with the temp sender wires removed for clarity) you can see the rail flange with the hex bolt where it's a suspect place for leaks. (you can see some sealant squeezed out on mine where it was fixed & resealed many years ago, I didn't just want to trust another new gasket)
Hope this helps?