Have a look under the oil filter see what the hose is like down there or one of the heater hoses in that area, could be from the EGR cooler on other side..... mind 2013 was a time of change under the bonnet of the Grand so some seem to be a bit of a Hybrid with old model and new model as gear box, turbo and a few other changes were made.....
With a high intensity small led torch the best way is to just do contortions and try to look everywhere and follow the snail trails before doing any pull downs on a guess...
Is it leaving a pool on the floor or just a drop ???
Someone on here thats had the oil cooler hose leak shoould chime in and be able to advise on the coolant trail left by it........ the hose can be sourced from Supercheap using a Commodore hose cut down, $30 ? you will have to find the thread its on as I'm on the road and forgot by Jeep Folder....
This thread page list the Holden hose part and details
http://www.ausjeepoffroad.com/forum/...=159876&page=2 and this thread
http://www.ausjeepoffroad.com/forum/...nt+Leak&page=6