Re: Engine issue
When moving, when going, I assume you mean when you are driving down the road. At what speed or all speeds? Has the transmission shifted thru all the gears when you hear or feel the strain. Has the transmission shifted at all per your suggestion "the engine is running at high rpm's". Do you have a check engine soon light on? Any error codes stored? How many miles? Did you just get this Jeep and perhaps you have no idea how it has been maintained? Has it been maintained or in other words plugs, oil changes, etc. A slug of water with a gas tank fill might cause some problems! Did you by chance pump in some E85 fuel. A vacuum leak usually sets an error code. The leak if you have one can come from any of several different places within the Emissions Control System. I had a leaking hose in the back just over the back drive axel housing. The vaccuum canister is just in front of the back bumper in the Overland with the 4.7 HO engine. It might be hard to hear a vaccuum leak, but they can give you fits.
Pay attention and follow up with some more information. I'm sure someone here can help ya. This is a great group of Jeep owners willing to help each other all the time.