Jetta TDI, fuel supply fault

SOURCE: 2003 vw jetta tdi fuel filter

It is on the passenger side right behind the washer fluid fill tube. You can follow the fuel lines (look like 1/4" black tubes, some are clear) from the injector pump to it. It is a caniser a bit bigger than a normal looking oil filter and sits between the washer bottle and the metal that forms the wheel well. It is held in by a screw type clamp about half way down the cylinder. Probably isn't the fuel filter unless there is air in the lines to the injector pump or they didn't bother to fill the fuel filter up with diesel after putting it in. There is not a fuel pump in the tank in these cars so everything is sucked up by the injector pump and it needs to be primed properly.

SOURCE: air in fuel line between fuel filter and injection

Hi, before the pump it is a loose connection or maybe a pin hole in the pipe, check all the connections and pipes for seepage, after the pump it will be a leak, i knowit sounds the same but after the pump the fuel is under pressure. It would appear that your system drawing air rather than forcing air in. daveg

SOURCE: How do you know if the fuel pump needs to be

Best thing to do is a fuel pressure test, the car does not have to be running to do the test just turn on the key. You can rent the pressure tester at auto zone.

SOURCE: 2002 Jetta TDI, has 180,000 miles. Engine sputtered and cut off.

standing at the front of the car pull the cover off the left side of the motor and check the belt. No tools are required the check the belt. Cover pulls up and off. It's to the left end of the valve cover.

SOURCE: 2006 Jetta TDI Tiptronic Maintenance

The tiptronic is not the DSG - two separate transmissions. You don't need to service the tiptronic every 40k like you do the DSG.
VW considers the fluid in a Tiptronic tranny as "lifetime" fluid - it doesn't need to be changed.