Most likely valve cover gasket, but check the CV boot too, they have also been known to let go. New axles are about $80.00 at the auto parts store.
219,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
Engine Build - Click Here