I have a 2000 1.8l A3, and a few months ago the starter motor started to fail (makes that whirring sound when it starts up). Not long after, another problem started where it had trouble starting at all. A few times a week it'd just turn over as long as the key was turned, but could take maybe 10 seconds before it finally started. Once it did start, it was at really low revs so I had to rev it (which felt really, really rough) to get it going. It would also randomly rev itself to about 3000rpm while I was driving once in a while.
Besides the starter motor, the other problems seem to have gone away, but now it has another problem where the battery dies every so often when I start the car. I turn the key, nothing happens for a second, then it starts but all the clocks have reset to zero as if the battery had died.
Sorry for the long post, I know the starter motor needs replacing but I'm not sure if any of the other problems are related to that or each other. I need to sell this car because I can't afford the petrol costs, but I don't know if any of these problems are serious and whether I really need to fix them.