You might want to check your injection pump timing that can affect fuel economy and power. The earlier VW pumps (80s-90s) is adjusted the same way if you don't know how to do it (requires specialty tools) find a good VW mechanic who works on diesels he will be able to help. As for the Vibrations, it could be anything, maybe pull back the T-belt cover to make sure your balance shaft belt is still in place and OK, clutch fan frozen or bearing gone. The list could go on forever and you need to get a trained ear to listen sometimes. Preferably one you can trust. <img src="/forums/images/graemlins/cheers.gif" alt="" />