Kia sorento shaking

Engine or transfer case are the only two suspects. (if you don't have a 4WD then just the engine). You might have a bad engine or transfer case mount. If the engine in the cause, a mild tune up may help - plugs, wires, clean injectors, clean all filters, check for vacuum leaks.

Thanks i will try this i just thought it was weird that i can feel it shaking more in the rear seat than in the driver seat.

If you have vibration when stopped or parked, then it's not caused by any wheel assembly or drive shafts. I've also read that if the vibration is coming from the engine it may be a stepper motor, part of the idle air control valve. The IAC changes under varying loads at idle, such as AC on or off, in gear or not. Try playing with those and seeing if the vibration changes.

Awesome good info thanks

Hope it helps! Another tip, to check for a bad motor mount, is to pop the hood and watch the engine while a helper shifts it into gear (with foot on brake obviously). Watch if the engine moves or shifts to any large degree. It's not a foolproof method but it may help reveal or bad mount.

I have a 2005 kia Sorento it shackes bad once I turn it on. And when I put a.c on it shackes a little more. I know for sure the motor mount in the back is going out. Do you think its that.