I know a few people with 2001 1.8t with the same issue. Try having the ECU updated.I had this done cause they told me there was new version to resolve this issue and other issues too.Issue was resolved after update. LOCal dealership should be able to do this.It ranges in cost my was $104 for the update. If it's an automatic transmission, I had a similar problem where it seemed like it didn't want to shift. It turned out to be a speed control sensor that was going bad. I warmed my jetta up a couple mins before it started to shift correctly. Try checking that.