I don't suppose these are  permissible hairline cracks  .

I would run it all aluminum heads crack as long as it isent cracked in to a water port or goes past the valve seat into the port on the other side of the valve seat I would say it's fine the exhaust side looks more like a casting flaw then a crack I would smooth everything out in there while its apart but that's just me

 

On a second look is the valve seat cracked too if so its new head time or a machine shop could possibly fix it

Edited February 6, 20179 yr by ferp420

This attached  pic  highlighted  spot appears to show the valve seat cracked  as well.  I will still disassemble it and check further  .   This   1991  loyale  ea82   spfi engine was cruising at  55 mph  and started shooting out steam coolant  and oil .  no  water in the oil pan  .  immediately shut down.  no overheat .  I suspect  the head  is  cracked  to the coolant passage . 

It is toast. It looks like it cracked all the way through. I don't remember ever seeing a crack in the exhaust port. That is no bueno.

Done.

The head side cracks are normal

The exhaust side is not.

 

And you've got all the symptoms to prove it.

I have no idea how the hardened steal valve seat could crack but it definitely looks cracked I would think the valve would give up first good luck with this

I had one do the same thing. Opened it up and behind the valve was a hole I could stick my thumb through. Of course it was a ea82T but didn't have any luck with the heads once you see the crack. I had a machine shop weld and reground but it happened again later down the road. 

I upgraded to a better engine. 

He's dead, Jim