I started my car last night and got a horrible grinding sound that continued for about 4 minutes after the engine started. It came on as soon as I turned the key. I immediately turned the motor off, but the sound kept going, so I decided to drive it back home and leave it there until I could get it into my local Ford shop. What is wrong?? Is it the starter? I think that is possible since the last few weeks, the engine has taken a few seconds to start...Thanks for any and all help