I own a (fairly stock) 2003 Nissan 350z with the VQ35DE. My z has about 123,200 miles. When I replaced my spark plugs and coil packs around 117,000 miles, I noticed in the #5 cylinder (I believe, it was the far back passenger cylinder, if facing the car) spark plug was submerged in oil. I am not seeing any oil leak outside the cover and that spark plug was the only one with oil around it. I have been scouring through the internet to see if I need to replace the valve cover gaskets or if I need entire new valve covers and gaskets. I am really confused on what to do and haven't found a straight answer. Do you think I should just replace the gaskets or replace the gaskets and covers to be safe?