My Ford van started hesitating when I accelerated and the check engine light came on. It was a bad coil on cylinder 5. Mechanic also replaced the plug and suggested replacing the fuel filter. I said ok.
But does a fuel filter gradually get contaminated? Or does it get clogged all at once when bad gas goes through?
I know fuel filters are notorious for stranding cars on the road. My dad got stranded on a country road one time and had to walk a couple hours for help. He had a 2nd after market filter installed to catch debris before it reached the tiny gas filter Detroit installed.
I’ve heard you can punch them out with a screwdriver in an emergency? Just to get fuel through them. That is if you know where in he heck the fuel filter is on your particular car.
Seems to be a matter of opinion among car folks, but the fact that most cars don’t have set fuel filter change intervals would suggest that most car makers think the latter these days.
However, I think there is a good reason to change the filter every once in a while: corrosion. At least in this part of the world, a fuel filter that’s been riding around on the bottom of the car for a decade or more becomes pretty darn near impossible to remove. I don’t think the screwdriver thing is a good idea (especially if the problem is indeed bad/dirty gas), but if you do have a weak fuel pump often putting a fresh fuel filter on will be enough to get you home. But the fittings being rust-welded on can turn that from a fairly easy side-of-the-road job to a small nightmare.
Both a gradual buildup of dirt or a bunch all at once can happen.
I had a new car in 1978 and filled it up with gas. I didn’t pay attention to the construction work being done next to the gas station until my car stalled out about 10 miles later. Somehow the construction work punctured the gas station’s tank and let mud in. My new car required the entire fuel system to be cleaned out including rebuilding the carb. The fuel filter wasn’t enough to stop smaller particles from getting in.
I use to work at a gas station and one of the jobs was to dip a long wooden pole into the tanks to see how much gas was in them plus how much water and dirt sediment. We put a paste on the pole which would change colors when it hit water plus dirt would stick to it. If the water or dirt hit a certain level on the pole, we would call in someone to clean out the tank. With alcohol in a lot of gasolines, I doubt if water is much of a problem anymore but dirt still could be.
There’s an old mechanic’s tale about not buying gasoline while a truck is filling the station’s tanks. The sediment that I talked about above could get stirred up. Might be true but I think the sediment would quickly drop below the fuel pump pick-up points which are situated above the bottom of the tank about a foot or so.
I use to change fuel filters as a matter of routine maintenance when they were easy to get at. My most current cars have the fuel filters inside the fuel tank as part of the electric fuel pump assembly. If the car starts running badly, then I’ll mess with the fuel filter.
You’re correct that getting a fuel filter off after many years can be write a pain. Before you try and remove the houses from the filter squirt a bit if WD40 on the ends of the fuel houses where they connect with the filter. Let it soak for a few minutes and your job becomes much easier. It is amazing what a little bit of penetrating oil can do.
If you use actual penetrating oil and not WD40, it works even better
(I know WD40 now makes an actual penetrating oil as part of a larger line of products…but the ol’ blue can Grandad kept in the garage is a pretty lousy one.)
