There was a ton of warning signs of Ed's coolant sealing problems.  A biggie was pressure in the system after the engine cooled completely down (like next day) The picture on my website (it's a boy!) shows the clue.  There were other signs as well but it is human nature to hope that it was not the worst case possibility (Coolant O-ring problem).   But don't jump to conclusions yet, we still don't know what it was.

 

Tracy (BMW had bad crank sensor