How to Change Your Fuel Filter
A clogged fuel filter is like your car having a clogged artery. Or maybe a clogged urinary tract. Either way, it’s bad.
If your car’s engine is sputtering, stalling, or hesitating and you can't remember the last time you replaced your fuel filter, that could be the problem. Changing a fuel filter that's integrated into a car's gas tank can be a bit of a bear. But if you're dealing with one that's further down the fuel line and can come out on its own, you're probably looking at a pretty straightforward swap.
The fuel filter plays a vital role in your engine’s operation and longevity ensuring no contaminants and particulate matter, like rust and dirt, enter the fuel system. Most fuel filters are enclosed in outer steel shells with inner paper filters, similar to the design of your car’s air filter.
Replacing a fuel filter isn’t as complicated as it may seem, though like most DIY maintenance jobs, following the right steps is critical to your success and safety. To make things easier, The Drive’s crack How-To team is here to help you change your fuel filter, and get back on the road. Ready?
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- Estimated Time Needed: One hour
- Skill Level: Intermediate or novice (depending on the car)
- Vehicle System: Fuel
Working on your car can be messy. It can also be dangerous as liquids can be flammable—bye, bye eyebrows, or worse. Here’s what you’ll need to ensure you keep your jeans, shirt, and skin spotless, and your bones fully intact.
- Nitrile gloves (to repel gasoline).
- Long-sleeve shirt to protect your arms.
- Safety glasses.
Organizing your tools and gear so everything is easily reachable will save precious minutes waiting for your handy-dandy child or four-legged helper to bring you stuff.
You’ll also need a flat workspace, such as a garage floor, driveway, or street parking, that’s also well-ventilated. Check your local laws to make sure you’re not violating any codes when using the street.
Everything You’ll Need
We’re not psychic, nor are we snooping through your toolbox or garage, so here’s what you’ll need to get the job done.
- New fuel filter
- New fuel lines, if the ones in use are at all ratty.
Here’s How To Change Your Fuel Filter
Let’s do this!
- For better clearance, lift the front end of your car with a floor jack, if needed.
- Locate the fuel filter. Check your car’s repair manual if you are unsure where it is.
- Remove fuel pump relay in the fuse box, this will allow you to depressurize the fuel system. The fuse box will be either under the hood or on the firewall inside the cabin. Check your owner’s manual.
- Start the engine and let idle until it stalls. (This may trigger the check engine light.)
- After the engine stalls, crank it for 5 more seconds to release fuel pressure.
- Turn ignition off.
- Disconnect the cable from the car battery's negative terminal. To be extra safe, disconnect the positive terminal as well.
- Place a drain pan under the fuel filter; some vehicles will leak continually until everything is reconnected.
- Use a screwdriver to detach fuel line hose clips; don't kink fuel lines as it could cause leaks later.
- Loosen fuel filter clamp.
- Disconnect fuel line fittings.
- Remove the fuel filter.
- Replace the old filter with the new fuel filter, making sure you install it with the arrow pointed in the correct direction. Check your car’s repair manual if you are unsure.
- Reattach clips.
- Secure clamp.
- Reinstall fuel pump relay fuse.
- Reattach negative terminal.
- Lower the vehicle, if needed.
- Turn ignition to accessory, NOT ON.
- Turn ignition off.
- Turn ignition to accessory again, NOT ON, to bring pressure to the filter and system.
- Check for leaks under the car.
- Start engine. Expect rough idle at first.
- Check for more leaks.
- Take a test drive.
- If everything is A-OK, you’re done.
Tips and Tricks
You can probably remove an inline fuel filter with whatever screwdriver you've got laying around and your bare hands. But you might find that a ridiculously tiny Phillips-head screwdriver (like this) and a hose-separation tool (like this) can make your life much easier.
Be prepared for some gasoline to spill out of the old filter when you remove it—handle it carefully.
As you remove fuel lines from the filter's nipples, you're going to want to twist and pull (not just yank) carefully to break the lines off the filter.
When it comes time to install a new filter, make sure you triple-check that you're putting it in the right way. Almost all of them should have an arrow and an indicator that says which way the fuel's meant to flow. That is, obviously, from the tank toward the engine.
Finally, once it's all buttoned up and you're sure the lines are secured, you're going to want to prime it before attempting to start the car. On my Z, this was accomplished by turning the key to the on position (without starting) about four times before cranking it over. Your car likely works similarly.
If you're lucky enough to have a buddy helping you, make sure they're watching the lines you just installed for leaks. If you're solo, hop out right away and inspect while the car's idling. If you've got even the slightest drippage, check your work and make sure everything's tight.
Many people advocate for replacing fuel lines if you've got the filter off. You'll have to make your own judgment there based on the age and appearance of yours. But if they're suspect at all, we'd recommend changing them. A fuel leak, especially one in the engine bay, is a serious problem you want to avoid.
What Could Cause a Clogged Fuel Filter?
Rust from somewhere in the fuel system, running poorly refined cheap gasoline from a sketchy pump, or letting a car sit for months on end can ultimately clog your fuel filter. But even under perfect conditions, they have a finite lifespan and eventually just need to be replaced. Generally speaking, it's common to replace them every couple of years.
Here's a great visual from Youtuber Chris Fix on how much of a hindrance an old filter can be to your car's fuel flow.
Tips From a Pro
Here are our top pro tips to help you replace your oil filter.
- Make depressurizing the fuel system easier by changing your fuel filter while the gas tank is below ¼ full. The almost-empty system won’t have as much pressure.
- To dispose of the leaked fuel, locate the nearest hazardous waste disposal center.
Since you may not have access to the right tools, we also compiled a list of our best hacks to make your life easier and drain your pocket less.
- Fuel filters aren’t created equal, look through the reviews of filters before buying one.
- Don’t use anything that could cause a spark and ignite fuel vapors (e.g., a garage light with a frayed cable).
How Often Do You Need To Replace Your Fuel Filter?
For new cars, check the owner’s manual for the recommended service interval. Generally, older cars require a new filter every two years or 30,000 miles.
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