I have a 2016 Jeep Renegade, I bought it used with 59k and the only real problem is when I stop at a light with it in gear, it vibrates, I had the fan replaced as per recall, serviced, and it still does it. They tell me it may be the fuel system? maybe dirty injectors, carbon buildup??? I can't afford the ridiculous shop prices here in Washington at 75 and on a fixed income....any help would be gratefully appreciated.