6 Symptoms of a Bad Fuel Filter and What to Do About Them

A lot of car owners tend to underestimate the importance of fuel filters. Even mechanics sometimes spend days trying to figure out what leads to a particular engine issue, and they overlook a fuel filter as a potential cause.

Filters are a necessary stop that fuel needs to make before getting to an engine. However, if you don’t maintain them properly, they can damage the engine and cause serious and expensive problems.

So, you should make sure that your filter is always in pristine condition.

In order to help you protect your car’s engine, I created the article about bad fuel filter symptoms. You should definitely keep reading if you want to learn how to notice signs that you need to clean or change the filter and avoid issues like this one in the future.

Bad fuel filter symptoms and what to do.

What Does a Fuel Filter Do?

A fuel filter gets rid of any dirt and debris from the fuel. That way, it prevents the dirt from getting into injectors or a combustion chamber. A fuel that isn’t filtered can be contaminated in many ways, from dirt and rust to paint chips. If the fuel stays contaminated for some time, harmful particles can cause the failure of the injectors and the fuel pump. Thus, fuel filter improves the performance of the engine and is a crucial part of the vehicle.

So, it’s important that you maintain your car’s fuel filter regularly. In most cases, you’ll just need to disconnect the filter and replace it with the new one. It will be helpful to know that a lot of filters nowadays are washable. Therefore, you’ll save money on buying a brand new filter.

However, a bad fuel filter can cause a restriction in the fuel flow. As a result, the engine wouldn’t be able to perform properly, which could lead to more serious problems with the vehicle.

Depending on your driving and living conditions, your filter will probably last you up to about 30,000 miles. Some filters are located in the fuel tank. They’ll be harder to replace, but they are more durable than regular filters. Thus, you can drive for 100,000 miles without worrying about your fuel filter.

But, there’s no rule on how long a fuel filter can last. Therefore, it’s crucial that you regularly check the condition of your car’s filter.

Your vehicle came with a manufacturer’s manual. It will probably contain information about how often you should replace the filter with a new one. So, you should consult it in order to avoid engine damage caused by an old and dirty fuel filter.

How Does a Fuel Filter Actually Work?

The filter works by pumping the fuel and removing the dirt from it. To do that, the fuel filter needs a pressure that a fuel pump creates. This part of a vehicle is made of a special material that blocks out dirt while allowing the fuel to pass through it.

If you’re assuming that filters aren’t necessary, because fuel is already refined, I need to let you down. Filters are important because fuel absorbs dirt and impurities during transportation and storage. Furthermore, your car’s tank usually picks up dirt and other things that can be harmful for the engine.

As I mentioned above, the fuel filter is an integral part of the process of fuel getting to the engine. Therefore, you can usually find a fuel filter anywhere along the fuel line of a car, between the fuel tank and fuel injectors.

However, some cars have a filter that integrated into the fuel tank. If you have trouble finding it, you can read your vehicle’s manual. It’ll give you all the necessary information about the location of a filter on your model.

6 Common Symptoms of a Bad Fuel Filter

Now it’s time that I present you with the list of symptoms that can indicate that the filter needs your attention. However, the deal with fuel filters is that there aren’t any clear signs that will show that there’s an issue with them.

Therefore, if you experience some of these issues, you’ll probably have to check your whole engine. That way, you’ll make sure that the filter is actually what’s causing the problem.

1. Your Car’s Engine Isn’t as Powerful as It Used to Be

A major drop in the engine’s power can be a clear sign of a fuel filter issue. If you’re on a bridge or driving uphill, and you notice that your car isn’t responding the way it used to, it’s time to check the filter.

A decrease in power occurs when the fuel supply from the tank can’t meet the demand of an engine due to a clogged fuel filter. The problem is more visible when your engine needs additional power to work or push the vehicle up. Thus, in case you notice changes in your car’s power, bridges and hills are perfect for checking if there’s any problem.

Even though a decrease in power can be a sign of different problems, it’s best that you check your fuel filter first. You’ll easily be able to see if there’s anything wrong and it won’t cost you much to fix the issue.

2. The Check Engine Light on Your Dashboard Turns On

Some cars have sensors that will turn on in order to let you know that there’s lower fuel pressure in the vehicle. A damaged fuel filter can put a strain on the engine. If a filter is clogged, there will be a smaller amount of fuel that passes through it. That means that the engine won’t get the amount of fuel that it needs.

The vehicle won’t be able to detect that there’s a problem with a filter. But, it can indicate that there’s an issue with or near the engine. So, if the light on your instrument panel is on, you should check your car’s filter along with other parts of the engine.

3. The Engine Randomly Misfires

There’s a chance that a clogged fuel filter can lead to a random engine misfire. When your vehicle is carrying a heavier load than usual or going uphill, the engine will require a large amount of fuel. If there’s a problem with getting additional fuel to the engine, it will be easier to notice in these cases.

However, it’s important to mention that a fuel filter can be the cause of misfire in special circumstances. This kind of problem can happen only when the filter is completely clogged. What’s more, your car needs to be under more pressure than it normally is.

So, if that’s not the case, another factor is more likely to blame for the misfire. Nevertheless, the misfire is a serious issue. You should get help from a professional in order to solve the problem as soon as possible.

4. The Engine Is Stalling

If your engine is stalling, the problem might not be as serious as you think. Similarly to the situation with the decrease in power, a clogged filter can cause this issue.

If the filter is too dirty, a larger amount of fuel won’t be able to reach the engine, which will lead to the engine stalling. It will most likely happen in more tense driving conditions because those cases will require more fuel.

Drivers often overlook the fuel filter when they experience problems with engines. So, if your engine is stalling for some reason, don’t forget to check the filter.

5. The Engine Won’t Start

There are many different reasons why your engine won’t start. A dead battery, bad starter, broken fuel pump, and problems with spark plugs are just some of them. Besides these causes, you should be aware that clogged fuel filters can lead to serious engine issues, and they can even damage it to the point of not being able to work.

Therefore, if your car’s engine won’t start, you should add fuel filters to the list of things you should check. When damaged, they can really mess up the process of fuel combustion.

In case your car’s fuel filter is dirty, but it’s not completely clogged, there’s a possibility that you’ll have a hard time starting your vehicle. This problem occurs when dirt restricts the supply of fuel, so the engine can’t get enough fuel in order to work properly.

As with every symptom on my list, having trouble to start your car isn’t a clear sign that you have a bad fuel filter. However, it will be useful to replace the filter and then check if you solved the problem. You’ll save some money and time on extensive repairs.

6. Your Car’s Fuel Pump Is Damaged

A clogged fuel filter can also damage your car’s fuel pump. Thus, in case you have problems with the pump, you should also check if the fuel filter is in good condition.

The filter that’s not able to work properly can put too much pressure on the pump and prevent the fuel from reaching the engine. As a result, there is a huge possibility the fuel pump will suffer in the process.

So, if the fuel pump of your car is damaged, it’ll be useful to examine the state of the fuel filter. That way, you can avoid problems with the pump in the future.

How to Check if Your Fuel Filter Is in Bad Shape

If you experienced some of these symptoms, it’s time to visit the mechanic and check the state of your car’s fuel filter. In case you reached the mileage I mentioned above, and you still haven’t changed the filter, you should do that as soon as you can.

There are fuel filters that come with a window. It will help you see the inside of a filter without getting your hands dirty. If the inside is dark and dirty, then you can be almost certain that it needs replacement.

You can also check if your car’s fuel filter is damaged by examining its external condition. Rusty and dirty exterior is a clear sign that a filter is in bad shape.

There’s also a special method that professionals use in order to check the condition of a fuel filter. The method consists of performing a fuel pressure test near the fuel injectors.

The performance is shown in pounds per square inch unit, which is called the psi, and it’s compared to the normal psi of your car’s model. If the number is smaller than it should be, it’s time that you change your fuel filter.

All in all, I recommend you to consult a mechanic regarding this issue. In case you are handy and want to examine the state of your filter by yourself, I found a YouTube video that might help you to verify if your fuel filter is the problem.

What to Do With a Bad Fuel Filter

There are many different factors that you should take into account before you decide what to do with your car’s bad fuel filter. I’ll mention the most important ones.

The decision on whether you should change or clean the filter can depend on its material. If the filter is made out of metal and you estimate that you would be able to clean it, then go for it. The worst thing that could happen is that a filter is too dirty to clean, so you’d have to order a new one.

Every car comes with a manual from the manufacturer. You can find useful information about cleaning and changing the filter as well as the recommended interval for replacing a fuel filter. So, if your car’s manual states that you need to replace the filter, do it.

Almost every symptom from my list is a clear sign that it’s time to say goodbye to your current fuel filter. If you experience serious problems with the engine, it’s safe to assume that you won’t solve the issue by simply cleaning the filter. The same goes in case of a significant reduction of power or when your car won’t start at all.

I believe it’s always best to replace the fuel filter. Fuel filters aren’t expensive, and you’ll get the insurance that the clog won’t happen for thousands of miles. So, if you have the option, my advice is that you change the filter.

What Happens if You Don’t Do Anything?

You’re experiencing minor issues with a fuel filter, and you plan to wing it until something more serious comes up? Well, I have to stop you right there. The filter isn’t just affecting the state of the fuel inside the car. It can do plenty of damage to your engine and the vehicle in general if you don’t maintain it properly.

So, what can happen if you don’t change the fuel filter regularly? Firstly, your engine won’t be able to perform like it used to. A clogged filter will make the process of fuel reaching the engine more difficult. Therefore, you can expect less power from your car’s engine.

In case the light on your dashboard that shows problems with the engine turns on, you’ll have to go through so many steps in order to find the culprit. That’s because the fuel filter is one of the last things that a mechanic would check. The process won’t be cheap, and it can be avoided by simply changing the fuel filter in time.

A clogged fuel filter can cause serious engine damage. If the filter doesn’t do a good job at removing dirt and debris, some of it can get to the engine. The fuel injectors can also become clogged, and they are harder and more expensive to repair than filters.

Thus, it’s important to maintain the fuel filter according to the manufacturer’s recommendation. That usually means that you’ll have to get a new one every year, even if you don’t have any problems with it.

If you do experience issues with a fuel filter, it’s necessary that you change it right away. Luckily, it doesn’t cost much, especially when you calculate the cost of repairing the whole engine.

Final Thoughts

I hope that we can all agree that a fuel filter is a significant part of the car. Its bad state can lead to issues with the engine. So, I made a list of the most obvious symptoms of a bad filter. That way, you’ll be able to address the issue as early as possible and avoid more serious problems.

I also provided assistance with figuring out how to check the filter. Furthermore, I  also tried to help you to decide whether you should clean or replace it. I have two articles coming on cleaning and changing the filter with thorough steps on how to properly solve the issue.



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