Project E36 M3 - Changing the Fuel Filter September 21 2013
If your car is down on power or sputters when starting, this may be a sign of low fuel pressure. That could mean a leaky injector, a failing pump or a dirty fuel filter. Since the filter is so cheap and easy to replace, it's usually the first thing to try. The fuel filter removes the dirt that would otherwise make its way down the fuel system where it can clog injectors or accelerate wear in your engine. If the fuel filter gets too clogged with contaminants, fuel has a hard time getting through, and you may have reduced fuel pressure at the engine. This means your engine will be running lean and not getting all the fuel it needs. Our E36 M3 didn't experience any of those symptoms, but it has been about 40,000 miles since the last fuel filter change, so it was time to swap it out with a new one. Before we started this job, we ran the gas tank down to nearly empty in case we sprang a leak that we couldn't stop. We also moved the car out of the garage. It's bad if your car catches on fire, but it is worse if your garage goes up in flames too. Good ventilation is important too, since there is going to be spilled fuel. As a good measure, we removed the fuse to the fuel pump and ran the engine until it died to bleed fuel pressure from the system.