One of the basic maintenance projects that you should perform on your Porsche is the replacement of the fuel filter. Starting in 2002, Porsche moved the filter to inside the gas tank and called it a “lifetime” filter that never needs to be changed. For cars with a replaceable filter, I recommend that you replace your fuel filter about once a year or every 10,000 miles. It seems that with today’s odd blended fuels, there always seems to be some gas station that has problems with dirt or grime in the gasoline that can clog your tank. I don’t think quality control with gasoline stations is really what it used to be. Needless to say, I try to replace the fuel filter at least once a year. If you have a 2002 or later car that needs a new fuel filter your only is to replace the entire fuel pump assembly. See Project 22 (Replacing the Fuel Pump)
Changing the fuel filter is not a job that I relish. It is almost guaranteed that you will spill at least some fuel on the ground and yourself as you swap out the fuel filter. Be sure to perform the replacement in a well-ventilated area. That means outdoors or in your garage with a few large fans blowing air both in and out. Have a fire extinguisher handy, wear rubber gloves, eye protection, and have a few rolls of paper towels handy—you will need them.
The fuel tank should be as low as possible—drive around until the gas tank is almost empty. This will minimize problems if something should happen to go wrong.
The first step is to jack the car up (Pelican Technical Article: Jacking Up Your Porsche 911 Carrera). The Carreras have an intelligent design when it comes to fuel flow. The fuel pump is located in the bottom of the tank and pumps fuel out of the top fuel tank cover. Why is this good? Well, when you go to change the fuel filter, you can pull out the fuel pump relay, crank the car a few times, and be assured that fuel isn’t going to flow everywhere if you make a mistake. Some older cars have a gravity-fed system that takes fuel out of the bottom of the tank. With these systems, you have to disconnect the line and clamp it very quickly—otherwise, the entire tank of gas will empty out! Unfortunately, with the Carrera system, you can’t get 100 percent of the fuel out, and some will spill when you disconnect the fuel filter. In addition, the filter itself will mostly be full of fuel too.
Now, crawl underneath the car. The filter is located behind the large plastic panel located in the very center of the car. This panel is held on with some plastic nuts (10mm head)—remove them and the panel should easily drop down. Next, remove the foam fixture piece that wraps around all of the lines in the center tunnel, and remove the two bolts that hold the plastic coolant line bracket (see Figure 1). Disconnect the fuel filter ground strap, and loosen up the clamp that holds the filter. Now you want to disconnect the lines to the filter. The Carrera filter has connections that are very easy to attach and remove. Simply push gently on the grey tabs on opposite sides of the plastic connector, and the connection should easily slide off. Take a close look at your new filter for guidance on how this quick-connect connector works. Have a small pail or bucket handy to catch the excess fuel when you release the connection.
When the connections have been released, expect quite a few ounces of gasoline to be coming your way. Be prepared (gloves, eye protection, paper towels, bucket, and a well-ventilated area). Take the filter out by pulling it toward the rear of the car, put it in your bucket, and take it and any left over or spilled gasoline outside of your garage immediately. Let the garage sit empty for about 15–20 minutes before you re-enter—it will take about that long for the fumes to clear. Then, simply reattach the new filter in place of the old one, observing the direction of the arrows located on the filter—they point in the direction of fuel flow, which is from the gas tank (front) to the engine (rear). Check that the snap-fit connections are properly seated by gently tugging on them. Reattach the ground wire (important!). Tighten the clamp that holds the filter tight. Then reinstall the foam piece and the large center panel.
Please note: This article does not apply to C4 models.
The filter (green arrow) is located almost dead center in the middle of the car, hidden somewhat behind the coolant pipes. The blue arrow points to the foam piece that needs to be removed so that you can pull the filter out toward the rear of the car. Removal of the filter is made easier if you remove the two screws that hold on the plastic coolant line bracket (yellow arrows). The orange arrow shows the screw that needs to be loosened in order to release the fuel filter from the clamp. The purple arrow points to one of the two tabs that must be depressed on the quick-disconnect connector. In the lower right, a brand new oil filter is shown. Note the arrows that indicate fuel flow direction printed on the side of the filter. The lower left inset photo shows the small ground strap that needs to be removed from the old filter and reattached to the new one (red arrow).