Guessing if the valve cover gasket is six years old it hasn't had a valve adjustment for sometime......I would do both....

Hard to tell where the oil is coming from but the most common causes are valve cover gasket and oil filter housing to block gasket......I thought my rear main seal was leaking because of the oil on the bell housing, but when I changed the transmission filter.....I noticed it was all because of the oil filter housing gasket....

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