Is there a solution to the continuing corrosion of the spark plug wells in the cam cover on my 1995 XJ6? Will they eventually corrode through? The car has 110.000 miles on it and I really love it and want to drive it for a very long time.

 

Yes, they will eventually corrode through. I reckon your coil/s will be arcing a spark to the cam cover which accelerates corrosion. Look for cracks in the coils. Have your cam cover painted. I've heard varoius suggestions over the years about how to insulate coils or prolong their life. Some suggest using the more modern spark plugs and fitting a rubber sleeve over the coil.
In the first instance, check the coils for cracks.