I've recently bought a corsa 1.2 16v. I noticed it wasn't starting too well, so took the spark plugs out for a look. They had been in so tight that when I finally did undo them, the insulating ceramic had cracked quite badly (probably due to me undoing them). What torque should these plugs be set at? I doubt I can get a torque wrench that goes low enough, so how tight roughly by hand is ok? I noticed all the plugs seemed 'lined up'. Is this anything to do with positioning of the electrode or just coincidence?
