I have a 98 GT with nitrous. I change my plugs every 3 bottles....and whenever i pull them out the electrodes look fine...no detenation...no nothing.....but this past weekend i pulled out number #7 (i think, its the driver's side rear plug) and the electrode tip was dry but the threads were SATURATED in oil (maybe mixed with a bit of fuel...judging by the smell), is this a cracked head? or maybe just something stupid? The car is running absolutely fine with no smoke or missing....HELP 


