I have had the car apart this week due to needing a helicoil and sorting out other underbonnet issues.
When putting the car back together today my brother and i noticed a small water stain under No3 exhaust port, looked in the head and you could also see some staining, also No3 on the exhaust manifold was white and the other 3 black.
Decided to take the head off and No3 piston had a nice pool of water and antifreeze sitting on top of it
Don't look like any damage to the gasket, the head has a few small cracks around the spark plug.
Might be the block but can't see anything

Steve