How to Know if Fuel Filter is Bad

How to Know if Fuel Filter is Bad

The fuel filter is a part of every car. Most of the vehicle owners will tend to forget about it as it’s situated in a hidden area that is under your car. It is easy to miss, even if you check the fuel tank.

It’s not listed on the top-priority car services, but things can go bad if you don’t look after it. When some problems arise, a clogged up fuel filter is not considered as a culprit in most cases.

But a bad fuel filter can bring a lot of car problems that you won’t realize at the moment you found something is wrong with your vehicle. It is the destination of all the fuel consumed by the engine.

The main purpose of the fuel filter is to catch all the dirt from the fuel injection system. So when it comes to the point of being clogged, it will immensely affect how the engine functions. It can even hinder your car from moving. 

It becomes porous as time goes by.

Obligations of Fuel Filter

The fuel filter takes any dirt or debris in the fuel before it proceeds to the fuel injection system. It is usually attached to some part of the fuel line while in some cars, it is placed in the fuel tank. 

The fuel pump uses pressures to send fuel to the filter. The fuel filter pump is composed of materials that are permeable and pleated. It lets the fuel to pass, but the dirt particles remain with it. 

The filter becomes less permeable and dirty as time passes by. It results in minimizing the amount of fuel that it can allow to pass so it can reach the engine. 

So these things show you how important it is to change your fuel filter. Some manufacturers would advise customers to change it after 30 000 miles. Some factors, like the driving condition and the type of diesel engine, can affect this count.

The fuel filter that is found near the fuel tank is expected to last longer up to 100, 000 miles. It is larger compared to the serviceable filter, and it lasts longer. However, it is not easily changed.

How Can you Tell if the Fuel Filter of Your Vehicle is Bad

1. Trouble in Starting a Vehicle

One of the problems a clogged fuel filter can bring is the trouble in starting a vehicle. It makes the flow of the fuel system inconsistent and even restricts the movement.

So try to remember the last time your filter was a new one.

2. Performance Issues of the Engine

The problem brought by dirty fuel filter mingles with the vehicle’s engine. The severe level of clog and dirt does these effects.


The clog in the filter and the heavy load is the reasons why the engine misfires. It simply means that it randomly hesitates to come on.

When some particles clog the filter, there’s a depletion to the fuel that is supposed to be fed to the engine. It’s remarkably obvious when your vehicle is in acceleration. 

Stuttering and shaking can also happen at any speed. The amount of fuel that contains the dirty filter differs in some ways. 


The early sign of stalling is when your engine begins to stall just a little time after you turned on your engine. Expect it to get worse if the clogged filter has been with your vehicle for a much longer time.

The clog undermines the fuel flow that goes to the engine. The heavy load and extra stress make it worse.

Acceleration and Power Decrease

You will notice the deficiency in your engine’s power, especially when the speed is up. A dirty fuel filter can restrict the engine’s computer in providing protection from the threat of damages.

It will make your car go limp or move slowly like it’s being burdened of heavy stuff. 

3. Check Engine Light

Some vehicles carry sensors for fuel pressure, which observes the pressure of the entire fuel system. So that’s why a check engine light occurs.

A clogged fuel filter drives low pressure so it will set out the check engine light for the driver to know. The sensor will activate this warning.

But the setting of this check engine light can happen in various cases. It’s recommended to have it scanned for the computer’s trouble codes.

4. Affected Fuel Pump

A restricted fuel filter would damage the fuel pump. There’s a lot of pressure that goes to the fuel pump. It restricts the adequate amount of fuel to get into the engine.

Results of Not Discarding a Bad Fuel Filter

As what was mentioned above, a bad fuel filter that is in use for a long time results in engine performance issues and the coming up of check engine light on the dash. A replacement of fuel filter is required at this point.

But it can come to the point of more damages. An old filter’s ability decreases so it won’t be able to catch debris and dirt, so internal breakage happens.

You will be surprised to discover engine damage that is quite serious, and you need to spend a handsome amount of money for its solution. So you shouldn’t just ignore the symptoms of bad filter fuel in the early stages. 

Be aware that you need to change it at least once a year. You must be alert regarding his matter, especially if you always let your car engage in high mileage and in extreme driving conditions. 

It will not end the life of your engine once you get it fixed in an early stage. 

Words for Closing 

Giving attention to your fuel filter is not a hard thing to do. You should include it in your car’s maintenance to avoid spending too much money on the worst scenario.

You don’t want to be surprised that your vehicle may behave in a strange way while you’re on the road. See to it that you deal with it in an early stage. It affects your engine, which is an important part that keeps your car functioning.

Leave a Comment

Your email address will not be published. Required fields are marked *