Updated at: 21-06-2022 - By: Lucas

The fuel filter is the part of a car that gets replaced the least. Every car, whether it runs on gasoline or diesel, has a fuel filter to keep dirty fuel from getting into the fuel injection system and clogging it up.

Most of the time, the fuel filter is hidden under the car or inside the fuel tank. It’s not in plain sight, so we often forget about it. Yes, it’s a cheap small replacement part, but when it breaks, it can cause a lot of trouble.

Some places are known for having fuel that isn’t very good. This means that the company’s advice about when to change the fuel filter is useless.

When the fuel filter gets clogged, look out for misfires, stalling, slower acceleration, and a loud fuel pump.

Some drivers, though, don’t realise there’s a problem until the fuel filter gets so clogged that the car won’t even start.

How does Fuel Filter Work?

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For any engine to do anything, it needs fuel. If something gets in the way of the flow of fuel, it can cause all kinds of problems.

High thresholds Due to their high-pressure fuel injection systems and many sensors, modern engines are more likely to be affected by changes in fuel pressure.

The fuel filter just catches the junk and keeps it from getting into the fuel injection system. The water around diesel engines is also more likely to be dirty. Because this is such an obvious problem, many diesel fuel filters also have a drain valve at the bottom of the housing to let the water out.

The fuel filter is in the line that brings fuel to the engine. There are two kinds of fuel filters, but both clean the fuel by using many layers of filtration paper. Only their housing is different:

With a cartridge-style fuel filter, both the housing and the filter itself can be taken apart. So, the only thing that needs to be changed is the filter cartridge. The new filter, which is made of paper, is put into the same housing.

Completely Replaceable Fuel Filter: This type of filter is made of just one piece, and the whole thing needs to be replaced when it gets dirty. Most fuel filters in new cars are like this one.

Some manufacturers have also started to use fuel pumps with built-in strainer-style filters. So, if your car doesn’t have a fuel filter, it’s probably built into the fuel pump.

To clean the strainer, one would have to take the pump out of the gas tank. But these filters are often marked as being good for life, so in theory, you shouldn’t have to replace them. In reality, though, these claims are often wrong because the fuel in some places isn’t very good. Even if the fuel is good, calling any part of a car “lifetime” is just a misleading gimmick with an asterisk*.

Symptoms of a Bad Fuel Filter

We often have problems with our cars that could be caused by a clogged fuel filter. When the fuel filter gets clogged, it stops fuel from getting into the combustion chamber. This makes the engine run out of fuel. Here are some signs that will help you figure out what’s wrong:

Acceleration feels sluggish

If you’ve had the car for a long time and notice that the engine’s power is going down, it might be because the fuel filter is clogged. The car might run fine in the city, but if you drive it on the highway at high rpms for a long time, the dirty fuel filter won’t let the right amount of fuel through.

After you’ve checked things like the spark plugs, MAF sensor, and air filter, it’s a good idea to see if the fuel filter is dirty. This can also happen if the oil pressure is low or if the EGR valve is broken.

When you speed up, the engine needs more gas. But if the fuel line gets clogged, the engine will run lean (too much air in the combustion chamber).

Lean engine combustion is also shown by a white deposit on the spark plug. Also, when you use an ECU scanner to find trouble codes in a modern car, you’ll probably get a warning that says “engine running lean.”

Engine Misfires under Load

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Misfires can also happen when you speed up if the engine doesn’t have enough fuel. Some cars will also make it more exciting by making loud noises from the exhaust. When you try to speed up in a car that isn’t running right, you’ll notice that the engine is losing power.

If you just speed up smoothly, the misfire might not happen. So driving hard in a higher gear is a good way to see how the engine works under load.

Engine Stalls

If the blockage is bad, the car may not even be able to be driven. It might idle fine, but as soon as you put it in gear and try to move, it will stop. If you don’t pay attention to the other signs of a dirty fuel filter, you won’t have this problem. Find out what to do if the engine gets too hot.

Noisy Fuel Pump

When there is a clog in the fuel line, the fuel pump has to work harder to move the fuel through the system. When the fuel filter gets clogged, the pressure in the fuel line goes up. This makes the fuel pump work harder. Most of the time, if you put your ear close to the fuel cap, you can hear the fuel pump making a whining sound.

All of these are also signs that the fuel pump is broken.

Some cars won’t show symptoms of a bad fuel filter

The people who make cars know that most people don’t change the fuel filter. Because of this, some cars have a way to get around a clogged fuel filter. So, even though the fuel isn’t properly filtered, the fuel pressure at the fuel injectors stays the same.

At first, this system might seem easy, but it can cause bigger problems. I wouldn’t want dirty fuel to go into the chamber where the fuel is burned. There is a good chance that something will get stuck in the valves or fuel injector. As you can see, if the fuel filter isn’t changed on time, it will cost a lot to fix. There are no warning signs until the injectors need to be changed.

Bad Fuel pressure regulator also show similar symptoms

The fuel pressure regulator is in charge of keeping the fuel rails at the right pressure. If the fuel pressure regulator is broken, it can also be a sign that the fuel filter is broken. They are all part of the same system, after all. Start by changing the fuel filter and then see if the problem is fixed. If not, you should have a good mechanic check the pressure regulator.

But sometimes a faulty fuel pressure regulator can also cause the fuel rail to have too much pressure. The car might then start to make black smoke, and the spark plugs might get black soot on them.

How often should you replace Fuel Filter?

Most car makers say that you should replace your fuel filter every 20,000 miles or 32,000 km. But every car is different. Some use big fuel filters that last a long time, while others use small filters that need to be replaced more often. Your car’s owner’s manual will tell you exactly what the company that made your car suggests.

Still, if you know that the fuel in your area isn’t the best, you should replace the fuel filter much sooner than what the manual says. Even so, they aren’t very expensive to begin with. Using cleaners for the fuel system often also helps. best cleaners for fuel systems on Amazon

Diesel Fuel Filter Requires more Attention

A diesel car’s fuel filters should be changed more often than other parts. Why? Because fungus and bacteria are more likely to grow inside diesel fuel tanks. Also, it’s a good idea to use fuel tank additives like Diesel fuel conditioner to stop microbial growth.

Will Bad Fuel Filter Throw Check Engine Light?

Yes, your car will most likely give you an error code if the fuel filter is clogged. The codes can mean that the fuel pressure is too low or that the engine is running too rich.

What are the signs of Clogged Fuel Filter?

Bad fuel filters could cause the engine to lose power, stall, misfire when under load, or make a lot of noise.

What kind of Noise do Fuel Pump make when filter is clogged?

When the fuel filter can’t supply enough fuel, the fuel pump has to work hard to keep up the right pressure. In this case, you can hear knocking or ticking sounds coming from the engine bay.

How Often should you replace Fuel Filter?

Many car manufacturers suggest fuel filter replacement at 20,000 miles or 30,000 km. If you think the gas in your area isn’t the best, it doesn’t hurt to check it every time you change the oil in your car.