I am also going to swap the plug to another cylinder . Have not heard of a plug just going bad. But all possibilities should be explored. Can't do much till Saturday. I know the coolant leak is at the back of the engine near the head on Drive side ,so I may skip the pressure test and just tear into it. I don't know how to tell if the block is cracked unless it very visible.
Guess we will be playing it by ear for now
Any reason to check exhaust gas in coolant? That would indicate head gasket failure or cracked block I suppose. But wouldn't a cracked block have shown up sooner after overheating? Everything was fine then all the sudden It was throwing the cylinder misfire code Stuck valve?? Maybe. Keep talking to me about this. What is the best plan of attack.
Thanks

 

Going to start looking into doing head gaskets if I can gather up enough tools. I have a question that may be dumb but if the heads are off and the block is cracked will it be visible or obvious? I am going to get the coolant pressure tester and a mirror on a stick and try to see if anything is obvious before starting to tear it down. This is a 99 with 220 K on it, I hope this works out .
This is not something I have done on my own before so I will be consulting the "FORUM" quite a bit. I love a challenge.