just a tip on prevention of falsing due to magnetised ingress of dirt or water,,,all i do is apply by the tip of my finger,,clear silicon sealant,,just a small bit at a time ACROSS the joint between the coil and the cover then after 3 or 4 inches smooth over to remove excess,,do that inside and out to completely seal coil from any ingress,,you can also do this to repair the areas that have been removed with use or cleaning and keep it ,,TOPPED UP,,works for me,,rgds comcat