1998 Saturn SW2 thud

I took my car to a shop and thought that the motor mounts were bad I told them there was a thud as I drove forward but the it stopped/ Any way I was taken for 535.00 and the problem still was not fixed so now I am trouble shooting to see if maybe it is a minor problem. I was told by the mechanic that it was OK to drive the car for a while like that. I felt like I had stupid written across my forehead.