I have a 2014 Jeep Grand Cherokee Limited, 5.7 liter. Second owner, obtained at 20k miles, currently at 43k. Since I got it… I’ve experienced problems. It could just be from the previous owner… but the Jeep dealership has not been helpful. The car is sluggish. It will sometimes hold an RPM and takes some time to finally shift out of it. Or if I need to gain speed the RPMS will go up, but not the speed. When I slow down & Attempt to gain speed again makes the car feel sluggish… as if stuck in a gear… a kinda of vibration happens then finally it shifts out of it. Every time I’ve taken it into Jeep the car presents no codes. And theysay they cannot “duplicate” the problem. Like of course your short test drive around the corner isn’t going to present the problem… sighs
Sounds like the lock-up torque convertor does not want to unlock or the system that shuts down 4 cylinders of the 8 to save gas isn’t working very well. I’d try a good local independent mechanic and have him ride with you with his diagnostic screen to he can capture what is happening. The dealer should have offered to do this, at a cost. That is the only chance of fixing this.
If that doesn’t work, I suggest you get rid of this vehicle and don’t buy another Jeep. Sorry.