Q: Car shaking

Vibration at idle is due to either failed motor/transmission mounts or an engine operating condition that causes a rough idle. If you are getting vibration through the steering wheel at speed, the most common cause is a wheel/tire imbalance although other possibilities include failed struts, other suspension defects (typically worn and loose parts) and possibly wheel bearing or axle failure if accompanied by lots of noise. The loss of power on acceleration is an engine controls/management problem and the causes range from worn spark plugs to partially plugged fuel filter, faulty oxygen sensors, faulty throttle position sensor, and so forth (quite a few possibilities). I would suggest you address the engine operating condition first and get that diagnosed and resolved as that may have a bearing on the vibration at idle. The service to request would be a loss of power diagnostic. At the time of the mechanic’s visit, if you desire, you can additionally request that the vibration at speed issue be diagnosed. As noted, that involves a whole different slate of components, namely the suspension system. The vibration problem might be resolvable by wheel balancing but you could have tire defects and, as noted, there could be worn suspension parts. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.