Part of routine maintenance on a Volkswagen Jetta TDI is replacement of the fuel filter for the high pressure injection system. If the fuel filter becomes clogged with dirt and debris, the carwill not return optimal fuel mileage and may run rough and eventually may not run at all. The fuel filter on a TDI should be replaced every 20,000 miles.
Change the Fuel Filter
Open the hood. The fuel filter is located on the passenger side of the engine bay in front of the coolant overflow bottle. Squeeze the fuel lines hose clamps with the pliers and slide the clips off of the lines. Push the fuel lines off of the metal lines on the filter.
Remove the fuel filter clip, which is located where two of the fuel lines come together and go into the filter. Lift the filter “tee” out of the filter. Loosen the screw on the sleeve clamp that holds the filter body in place in the engine bay. Remove the filter.