I bought a 1996 Saturn SL for my daughter for use at college. Everything was running fine until now. When hitting speeds above 40mph, the steering wheel has a little slight sudden pull to the left. She had a machanic look at it near the campus. She says he worked under the front end and told her that the screws were lose on one side and they tightened them up, they also said the other side was ok. The problem was resolved for a little while after this procedure but is now back. I have looked all over under the car to find what they might have "tighten" up. LOL. Nothing. Any Ideas?
Loose bolts on any part of the suspension or steering will result in more than a little problem. The mechanic may indeed have found something loose, but there has to be more to it than that. A pull that changes is the result of a worn part. Ball joints and struts are the most common causes but worn lower control arm bushings have been common too, especially on GM vehicles. Have the car inspected at a tire and alignment shop by a mechanic who specializes in alignment problems. Alignment problems show up right now as pulls and possibly an off-center steering wheel. Over time it shows up as poor tire wear. Intermittent problems that change over time, as you described, can be due to loose bolts but 99 percent of the time it's due to worn parts that could be about to separate leading to loss of control and crashes. Ford owners have been WAY too aware of that since the mid '70s.
Clunks and rattles are another sign that something is worn or loose. Many Chrysler and GM owners tend to overlook those noises for a long time because they get accustomed to hearing them with no other symptoms. You never want to ignore a squeak or rattle on a Ford.