I was cruising up an on-ramp, getting ready to merge into traffic when all of a sudden, the engine in my 2003 Jetta TDI began to bog down and lose power. The more gas I tried to give it, the worse the engine ran -- next thing I knew I was stuck on the side of the highway waiting for a tow truck. As it turns out, Volkswagen recommends changing the fuel filter on these diesel engines every 30,000 miles. I guess I'll have to start paying attention to my mileage. The plus side was that I learned how to replace my own fuel filter, and it was a much easier job than I had expected.
I figured I would take the easy route to release fuel pressure, and pulled the fuel pump fuse. It was fuse No. 28 in the main fuse box. After that, I started the engine and waited for it to stall, then removed the key. My parts guy had told me that my filter was under the hood, on the passenger side, and had four rubber hoses connected to the top of it.
I removed the clip for the valve on top of the filter, then pulled the valve straight up and out of the filter. I figured the two fuel lines connected to the valve didn't need to be removed, but the two connected to the filter itself did, so I removed those. I loosened the band clamp toward the bottom of the filter, and lifted the filter out of the engine bay. I replaced the O-rings on the valve -- the blue O-ring fit on first, followed by the black O-ring. I poured fresh diesel fuel into the filter to prime it, then pressed the valve into the hole on the top of the filter. I secured the valve with the new clip that was included with the filter.
