I just posted to similar question on this was there oil in the hole in other words when you put your whench down there doesd it come out with oil on it. even just a little indicates a bad vavle cover gasket. see when things like this happen they ussally happen to all plugs not just one or two and the valve cover gasket is very common on all high millage DOHC 4 cycl so check that first its cheap and simple.
