Welcome, and congrats on the new to you Durango. The seepage you saw around the intake could be from a sloppy oil change, or the common leaky upper intake gaskets. Be careful power washing around the engine, especially the top and wiring areas. Water under that kind of pressure can go places you do not want it to, and begin a nightmare. The '15s are known for water pump issues, so keep your ear out for any such noises.
If your power train warranty is still in force, the dealer will replace those gaskets for you.