If you have a Disco 2, that did not come with an oil cooler. Check the two plugs that were installed in the front cover in place of the oil cooler lines. Both of mine were hand tight and neither had a o-ring. One is between oil filter and oil pan, the other is above oil filter on passenger side. Both will take 7/8" socket or metric equivalent. Mine have been leaking since I purchased, after installing oem oil cooler, My oil leak disappeared. I had purchased front cover gasket, seal, timing gears and chain, oil pump, pan gasket for install. Am putting that off until I have some spare time and want to get dirty.