So, today I brought my TJ into Tim shot where I work and we ran some fuel cleaner through (not the kind through the gas tank, the pressurized stuff going directly into the intake). Did wonders, jeep idles better and runs smoother. So, to do this you keep your vehicle running and keep it a constant rpm,normally around 2 grand. This I did, and then revved it up some during. When it was done, I turned it off to unhook the machine, but when I started it up again, oil spayed out on the ground from somewhere. Dripped for about 150 feet while I drove and it burned off. Was worried, but then I let it sit for almost an hour and not one leak could I see, and no spots on ground. What do you think happened? I was going to replace valve cover gasket to be safe. Thoughts?