Take the cover off the top of the engine and look down beside the oil filter housing. You may need a light. If there is oil there it is leaking down the valley and around and down the bellhousing. I just recieved my dorman aluminum upgraded housing and plan on installing it soon on my wifes 2014 JKU sahara.
Yep, this is a common-ish leak that the 3.6 develops. Not just on wranglers, but in all versions of the engine. When I had a jeep with this engine, I used a video from a charger to diagnose it.
The oil cooler sits on top of the engine block, it also contains the housing for the oil filter. These fail, and the begin to create a puddle in the valley on top of the block. If you shine a flashlight down and near the oil filter housing to see the top of the block, you will be able to see the oil puddling.
Because of how the engine leans back just a bit, it will very slowly leak down the back of the block, making a diagnosis frustrating if you don't know what you are looking for.