Signs of a Bad Fuel Filter & How to Replace It

Technical

Oct 11th, 2021

Signs of a Bad Fuel Filter & How to Replace It

A car consists of several thousands of moving parts, all working together so you can travel safely and efficiently. While many of these parts live through the lifespan of the car, there are consumable parts that need to be replaced regularly, and one of those is the fuel filter.

Cars generally have four filters: air filter, oil filter, cabin filter, and fuel filter. To keep on top of your car’s maintenance and ensure everything works as it should, you need to know when a filter is going bad and what to do.

In this article, we're going to take a closer look at your car's fuel filter. First, we'll talk about the telltale signs of a fuel filter going bad. Second, I'll take you through 5 easy steps for replacing a bad fuel filter. That's a lot to cover in one piece, so, let’s get to it.

What Is a Fuel Filter?

The fuel in your car travels from the fuel tank to the engine where it's combusted to generate power. Somewhere along your fuel line is a filter designed to remove impurities or particles in the mix. Things like dust, dirt, and other contaminants might damage your engine if they weren’t filtered out. Thanks to the fuel filter, nothing but fuel gets to the engine.

Over time, however, the fuel filter will be clogged with impurities and become less efficient at its function. Fuel will flow less efficiently and lead to many issues.

What Are Signs of a Bad Fuel Filter?

Thankfully, it's easy to tell if you have a clogged fuel filter. Here are a few signs to look out for.

Inconsistent Power

Fuel will travel much more slowly from the tank to the engine, resulting in inconsistent power while you drive.

Check Engine Light

There are many reasons why your 'Check Engine' light might suddenly turn on, and a bad fuel filter is one of them. If a fuel filter is clogged and fuel can't move smoothly, your car’s engine can’t do its job either. So indirectly, a bad fuel filter will cause the 'Check Engine' light to turn on.

Engine Misfiring/Stalling

Fuel might flow slowly into the engine, or at certain times it might not flow at all. If you start to notice your engine misfiring while idling or driving, or even stalling completely, your fuel filter might be the culprit there.

Engine Doesn't Start at All

If the problem gets bad enough that absolutely no fuel can flow through the lines, your engine might not start at all. Of course, there are many reasons why an engine may not start. However, if all the other symptoms of a bad fuel filter occur with an engine that won’t start, they all point to one culprit – a clogged fuel filter.

Damaged Fuel Pump

A lot of the symptoms mentioned above are focused on the engine. However, if the problem gets bad enough, your fuel pump might also get damaged and stop working. The reason for this is straightforward. When you have a clogged fuel filter, the fuel pump needs to work extra hard to get fuel flowing through the lines. If this goes on for too long, the fuel pump itself will end up failing, too.

If somehow you find out that your fuel pump has become faulty, you will need a mechanic to inspect the entire fuel system and identify the cause. One of the possible causes he might discover is a clogged fuel filter.

How to Change Your Car’s Fuel Filter

The good news is that if you inspect your fuel system at the first sign of a problem, you might be able to avoid more serious problems. A fuel filter is quite easy to replace, either by a mechanic or by yourself at home.

Whether you're doing the fuel filter replacement by yourself or getting someone else to help, the process is the same.

  1. Reduce the pressure in the fuel line. You do this by disabling the electric fuel pump then starting the engine. First, you need to remove the fuel pump's fuse. Then, start the engine briefly to reduce the pressure in the fuel line.
  2. Disconnect the fuel lines from the fuel filter. Make sure you don’t skip step 1 before you disconnect the fuel line.
  3. Locate the arrow that shows the direction of the fuel flow. You need this arrow to make sure that you install the fuel filter correctly.
  4. Remove the screws that keep the old fuel filter in place. Replace the old filter with the new one. Once that is done, reattach the fuel line to the filter. Retighten any clamps used to hold the fuel lines in place.
  5. Reattach the fuse. Finally, you can put the fuse back in place.
  6. Do a final check. Before you lower the hood, restart the engine. While the engine is running, take a good look at the fuel filter that you just installed. Check both ends, especially around the fuel lines and make sure there are no leaks. If there aren't any, then the job is done!

As with most other car parts, a fuel filter is best replaced before it causes serious problems. An excellent way to stay on top of things is to have your mechanic perform a thorough check whenever you bring your car for regular maintenance. Most mechanics will have a checklist of items to be inspected, some more thoroughly than others, while they perform routine maintenance on the vehicle.

Use High-Quality Parts Every Time

For severely-damaged fuel pumps, engine components, or other car parts, make sure to replace them with high-quality spares. You don’t want to compromise on your safety and your car’s performance, no doubt about that.

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By Ray Hasbollah