You will hear the timing chain rattle if the tensioner is loose. It is unmistakeable. The tensioners operate with oil pressure. When the pressure is low, or the level is low, they will rattle. If the oil level is coprrect and you hear the rattle, run!
The upper torque axis motor mounts are rubber, and are notorious for collapsing. If the engine can be rocked front to back easily, or the car vibrates at idle, it's the mount. Cheap and easy fix.
Thay had a few problems with pourous block castings back then. The fix was a ginger pellet in the coolant to seal them up. Do not be suprised if the bottom of the coolant cap has a little "mud" on it. That is the pellet.
Gearhead is correct. You can also throw the diff pin through the trans case if you try to rock the car out of a ditch or snow bank by going back and forth between Drive and Reverse.
BTW. I was the Service Manager at a Saturn Dealership from '95 to '05.