2011 GMC sierra 1500
number 1 plug keeps going out. for a while we would replace spark plug and it worked for a while. now I replace the plug and it goes back out a few miles down the road. I replaced the wire. Thought maybe it was the wire because for a while everytime I would unplug and replug it would run for a while longer. I cant figure this our please help. Also my temp fan will come on all by its self randomly. has left me stranded at home a few times due to coming on in the middle of the night. Please anyone have any ideas....