Q: Vibrating when I stop 2007 Chrysler Pacifica

Hello - if you mean that the vibration occurs while braking, irregular brake pad deposits on the rotors (sometimes referred to as "warped rotors") are the likely cause. Worn suspension struts and/or loose steering links make this problem worse. Resurfacing the brake rotors and new pads, and making sure the steering and suspension system are within tolerances will eliminate this problem. If you mean the engine vibrates when you are stopped, engine vibration or rough running can be caused by a number of things - dirty idle air control valve, leaking exhaust gas recirculation valve, need for a tune-up - these can all cause rough running. I recommend a brake inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.