I tried to change the wire, but in the process I broke the plastic locking clips which hold the wire into the coil pack sockets. If I were to do it again, maybe I should spray some wd40 first. For now the new wire works with no problem, but I am not sure if the wire will come loose someday, since they are held in place by only half of the locking clips.
Also, when I insert the wire, should I use some ignition grease or heat up the wire end? It's really hard to screw the wire into the plug boots.
Thanks!