I have a 2006 Audi A4 Avant 3.2 with 83k miles. I went to install new spark plugs the other day and there was oil in the spark plug wells in both cylinder banks. I know the most common reason for this is bad valve cover gaskets, but I had mine replaced (both) by a reputable shop here in Chicago shortly after I bought the car in January of last year while the engine was out to fix a rear mean seal leak. Is there anything else that might cause this? Thanks for any help you may be able to offer.