While changing plugs in my 2007 LT 2.2, 2DR, Auto Trans, non "charged", Cobalt I was surprised to find what seems to be coolant rising in the #4 plug hole while tightening the plugs to the recomended 15 ft/lb. Does anyone know what the #!×;&? is going on here and what I can do about it? I have about 150,000 miles on it with zero problems save cleaning some electrical contacts on the door locks. Thank you for any information you may have!