I just purchased a 2003 jetta tdi, it test drove fine and the seller seemed real honest. After buying the car and driving home, the check engine light came on and lost power. Now every time I drive the car it goes into limp mode. I checked all the vacume and intake lines for leeks and they seem fine. Now I'm noticing moisture and black soot on the ground below tail pipe where the car had been idling. And the oil is black and greasy and there are air bubbles in the fuel line coming out of the fuel filter. How bad is this? do I need to rebuild the pistons and rings? This car has 105,000 miles and the oil looks as though it has not been changed for years. Is it possible that an oil and filter change can fix this? Im in northern Ca. does anyone know a good mechanic? [email protected]#@#^$#@^: