Re: 2003 Liberty Knock/Tapping
Welcome to the garage.
When you had the valve cover off, did you check for spongy feeling hydraulic valve lash adjusters? I would first get a mechanics stethoscope and try to pinpoint the source of the noise. At least you should be able to hear if its coming from the head area, the lower end or even from the flexplate (eventhough i wonder if the last would cause the mentioned noise)