Signs of a Bad Fuel Filter & How to Replace It


Jun 26th, 2020

Signs of a Bad Fuel Filter & How to Replace It

A car consists of more than a thousand moving parts, which all work together so you can travel safely and efficiently. What we tend to overlook is the fact that cars also have several filters in them. Cars generally have four filters: an air filter, oil filter, cabin filter, and a fuel filter. If any of these filters weren't doing their job efficiently, you wouldn't be able to use your car as you usually would.

In this article, we're going to take a closer look at your car's fuel filter. First, we'll look at useful signs you should look out for that indicate your fuel filter is going bad. Then, we'll explore how you could go about changing a bad fuel filter. But first, let's understand what a fuel filter is and what it does for your car.

What Is a Fuel Filter?

The fuel in your car travels from your fuel tank to the engine where it's combusted to generate power. Somewhere along your fuel line is a filter designed to remove any small impurities or particles in the mix. These impurities could be things like dust, dirt, or other contaminants that might damage your engine if they weren’t filtered out. Thanks to the filter, you can be sure that nothing but fuel travels through your fuel line.

As time goes on and the fuel filter does its job, it may become clogged with the impurities it filtered out from your fuel. If this happens, it will be difficult for the fuel itself to travel through the filter, which then leads to other problems.

What are the 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

If you've got a clogged fuel filter, the fuel will travel much more slowly from the tank to the engine. As a result, your engine will have trouble generating consistent power while you drive.

'Check Engine' Light

There are many reasons why your 'Check Engine' light might suddenly turn on, and the fuel filter is one of them. Think about it: if a fuel filter is clogged and fuel can't move smoothly, the engine won't be able to do its job efficiently. 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 the engine's failure to start happens together with all the other symptoms, that could be a clear sign that your fuel filter is to blame.

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 pretty straightforward: when your fuel filter is clogged, the fuel pump has to work extra hard to get fuel flowing through the lines. If this goes on for too long, the fuel pump itself might end up failing.

If somehow you find out that your fuel pump has become faulty, you may 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 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 significant issues. A fuel filter is quite easy to replace, either by a mechanic or by yourself at home.

Whether you're doing it yourself or getting someone else to help, the process is the same.

1. First, the pressure in the fuel line needs to be relieved. This is done by disabling the electric fuel pump before starting the engine. To do this, you need to remove the fuel pump's fuse. Then, the engine is started briefly to reduce the pressure in the fuel line. Once this is done, the fuel lines can be disconnected from the fuel filter.

2. Then with the new fuel filter in hand, you need to look for an arrow that shows which direction fuel will flow through. This arrow is vital to make sure that the fuel filter is installed correctly.

3. Usually, the old fuel filter will be held in place by some screws. These screws need to be removed so that the old filter can be exchanged with the new one. Once the new one is in place, the fuel lines need to be reattached to the filter. Any clamps used to hold the fuel lines in place will need to be tightened again.

4. Finally, the fuse for the fuel pump can be put in place.

5. Hold on a minute! Before you lower the hood, there's one final check that needs to be done. Once you've replaced the fuse, you can start the engine. As the engine is running, take a good look at the fuel filter that you reinstalled. Check both ends, especially around the fuel lines, just to 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 like these is to have your mechanic perform a thorough check whenever you head in for your 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.

For severely-damaged fuel pumps, engine components, or other car parts, make sure to replace them with high-quality spares. Searching can consume a lot of time, but of course you already know that. Have you tried CarPart’s Send a Parts Request feature? What it does is save you from the tedious process of searching for auto parts. So instead of going to all the sellers in the directory, you only need to fill out one request, and will find the part for you. Unbelievable? Try it now and see for yourself!

By Ray Hasbollah