AT-190L Oil wet the spark plug cable

If someone can help me; I have a 1993 Toyota Corona AT-190L model; 4A-FE Motor XLI. It is wetting the spark plug cable near the distributor inside but stuck above where inbone with the valve lid, only wet that cable worries that the oil can go down and wet the spark plug itself, what can this be due? I just changed the "or" ring towards the distribution.

If they are from the spark plugs with changucho, that is, those that enter the valve lid, this burned or hardened the packing of the valve cover, it carries some circles that cells with arriva the cone of the spark plug, it is very easy to change purchase the new cilicone and cover and problem solved, this problem is more dirty than dangerous It falls and throws smoke, changing it does not cost anything.