Q: Heard a loud noise while driving

While the amount of information provided for your Volkswagen is a bit limited, I can do my best to point you in the right direction. If the loud noise you hear while driving sounds rotational and it gets louder as you speed up, slower as you slow down, it is likely that there is a wheel bearing that is failing. If the noise you hear is not consistent with how fast you are going, it is possible that another suspension component can be giving you the noise you are hearing. To be 100% certain however, I highly recommend enlisting the assistance of a certified mechanic to perform a test drive on your Jetta in person. A test drive will confirm the noise and will allow them to pinpoint the problem area, identifying exactly why your VW is experiencing these symptoms. They will also be able to make the necessary repairs to eliminate the noise and get your Jetta driving smooth and quietly again.