valve cover gaskets....

Oil leaks are very hard to pin point.I thought my rear main seal was leaking also and I found out it was my oil pan which some how got a small pin hole in it and the oil was blowing back onto my bell housing leading me to believe that it was the rear main seal. Before spending lots of money thru the process of elimination,heres a tip that was giving to me which I did do. Clean your engine of all oil, go buy a bottle of UV engine Dye and pour this into your engine oil. Start your car up and let it run for a few minutes or if the weather is suitable drive it around the block. With a black light, I find it works best at night, shine the light on your engine and where its leaking the oil it will show up under a black light sort of a greenish color. This saved me money and time as I was about ready to tear off the oil pan... Good luck to you..