Ive been working on my altima (94) for awhile now, was just recently tinking a bit under the hood and i realized that both the number 3 and 4 have large amounts of oil ontop of the spark plug, i have a few of my own idea's but being this is my first foriegn car was wondering if im overlooking something

its your valve cover gaskets you have to get a new valve covver gasket set and make sure the little circle ones in the middle for the spark plug holes are set just take the valve cover gasket off and replace the gaskets itll fix it. and make sure you get an air compressor and blow the oil out of the cylinders then change ur plugs too. good luck.

I agree, you just have bad plug tube seals. They come with the valve cover gasket kit.