Clogged Fuel Filter (Causes, Symptoms & Fixes)

Clogged Fuel Filter

When your fuel filter (view on Amazon) is clogged, it is a very common problem. No worries, there is a solution that will clear your fuel filter issues. The fuel system in your vehicle is very important to the proper functioning of your vehicle. In fact, when there are fuel filter problems, it can stop your vehicle from running completely. If your vehicle has a clogged fuel filter, read on to find out how to fix it and get back on the road.

Why Do Cars Need a Fuel Filter?

What exactly is a fuel filter? A fuel filter is small component that is made up of a shell and permeable materials. The permeable material filters out particles that could be harmful to your engine. There are two types of fuel filter and either type of filter can be replaced.

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Both types of fuel filter work the same way as filtration mediums. Fuel filters are made of plastic or metal, with two fuel line connectors. Some fuel filter designs are the form of a cartridge with a filter inside a metal container. When the cartridge style of fuel filter becomes clogged, only the filtration medium must be replaced.

Automotive technology continuously changes to design of cars for the future, some things change while some things remain the same in the vehicle design. Most vehicles with an internal combustion engine still have a fuel filter. There are a few fuel filters that use a strainer that is attached inside the fuel pump to filter debris. In many modern cars, the fuel pump is located in the fuel tank. When fuel is injected into the engine, it must be clean and free of debris. The fuel filter may be located in the fuel tank or it may be found along the fuel line. Since internal combustion engines require injections of fuel that is in a certain state, the fuel filter ensures that the engine receives injections of clean fuel that is free of rust and debris.

Causes of Clogged Fuel Filter

Most vehicles have fuel filters that are made to last for 30,000 miles. Some diesel engines require a fuel filter replacement after every 22,000 miles. However, the mileage may vary depending on the vehicle make and model and how the vehicle is used. A few things can deteriorate the performance of the fuel filter or damage the filter completely. Here are the most common reasons why a fuel filter becomes clogged:

Debris – The fuel filter is designed to catch all of the debris that would otherwise enter the engine. Yet, the particles that the filter catches begin to accumulate in the filter over time and clog the filter. The debris may come from a rusted or contaminated fuel tank. The number of miles the vehicle can travel before the fuel filter needs replacing depends on the type of vehicle, the vehicle use, and the state of the fuel tank and fuel pump.

Low quality gas – The internal engine combustion process depends on the constant flows of the right amount of high quality fuel. Using low quality fuel into the fuel tank causes many different types of trouble. The low quality gas leaves huge amounts lof polymeric residue, which clogs the fuel filter and it is especially damaging to diesel fuel filters. The clogged filter also causes blockage in the fuel lines.

Fuel filter plug – The fuel filter also removes debris and water from the fuel in the diesel engine to improve the quality of the fuel. The diesel fuel filter also filters bacteria, which is often found in the interface between the fuel and water and helps save the engine from operating in rough conditions. When the diesel fuel filter plugs, it will stop the truck from moving at all.

Negligence – Vehicle manufacturers recommend when the fuel filter should be replaced. When that time passes and the vehicle has not been serviced, the fuel filter is clogged and will cause problems in the fuel system. Newer models have fuel filters that last much longer. Still, all cars need to be serviced at different intervals through the year. When the vehicle is not serviced, it’s likely that the fuel filter has built up enough debris to become clogged and will eventually cause problems.

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Symptoms of Clogged Fuel Filter

Internal combustion engines require air and fuel in specified amounts to run properly. When the mixture lacks air or fuel, the mixture causes noticeable problems. A clogged fuel filter affects the amount of fuel that enters the engine. When the filter is clogged, you will notice these symptoms:

Check engine light – The engine control module (ECM) determines the amount of fuel should go to the engine using the Fuel Rail Pressure Sensor. When the clogged fuel filter changes the amount of fuel that is going to the engine, , the ECM activates the check engine light on the dash. The light is activated because the clogged fuel filter decreases the flow of fuel to the engine. If the fuel filter is severely clogged, the ECM may reduce the engine output to Limp Mode.

When the diesel fuel filter is clogged, the water concentrations in the diesel fuel increases. The water-in-fuel sensor identifies the problem and the “water-in-the-fuel” warning will activate on the dash. The warning is about buildup that has clogged the fuel filter.

Strong fumes – When the fuel filter is clogged, it will cause odorous fumes that come out of the exhaust. After driving the car, it will smell like a gas station. The clogged fuel filter can cause a leak that smells like gas. This strong smell of gas could also be because your vehicle has other problems in addition to the clogged fuel filter.

Little or no idle – A common symptom of a clogged fuel filter is little or no idle. The vehicle may start right up, but when you come to a stop, the engine will shut off rather than idle. When the engine does idle at a stop sign or light, it will sputter instead of idling smoothly. This is definitely a sign of a clogged fuel filter.

Misfiring – When you step on the gas, there is a bit of hesitation. The engine is not receiving the right amount of fuel because of the fuel filter is partially clogged. There is not a full, continuous flow of fuel. When the fuel feed is abnormal, the engine will misfire. While driving, the engine is misfire occasionally because there is not enough fuel at that moment. This causes the engine to misfire. This will happen especially when you are driving at high speeds as you will feel the engine hesitate for a second or two and then resume.

Engine won’t start – When the fuel filter is fully clogged, at first you will have a tough time getting the engine to start up. It takes multiple cranks to get it started. During the more advanced stages of the engine receiving the mixtures of not enough fuel, the engine will not start at all because the signal timings and the flows are no longer accurate. This is why a clogged filter directly can seriously engine performance. The few times that the car does start, the handling will be rough.

What To Do About Clogged Fuel Filter

Any car owner wants to keep their vehicle running smoothly over the road. When problems come up under the hood, it’s time to find solutions. A clogged fuel filter is not a problem that cannot be fixed, especially if you find the problem early. Ignoring that clogged fuel filter is just going to cause more problems in the fuel system. Here are the most common things that you can do to solve the clogged fuel filter problem:

Regular servicing – The owner’s manual for your car will tell you how often your vehicle must be serviced and the type of services that should be performed. When you have your vehicle serviced regularly, as recommended by the manufacturer, it will ensure that those clogged fuel filter problems can be prevented. Routine servicing by a professional with a computer will expose a fuel filter that is becoming clogged. The technician can even recommend the right products or services after performing routine inspections.

Use OBD2 codes – Make sure that the problem is the fuel filter before you start making repairs. Use an OBD2 Scanner (view on Amazon) to find out if the fuel filter is clogged. The scanner can present several codes that relate to the fuel filter. These are the same OBD2 codes that a technician will look for if you take your vehicle to a repair shop. One of the most common OBD2 that are thrown when the fuel filter is clogged is the P0171 System Too Lean (Bank 1) trouble code.

Fuel cleaners – In mild cases, the contamination that is clogging the fuel filter and the fuel injectors can be remedied by using a fuel injector or fuel system cleaner. Using the cleaner will also remedy debris inside the fuel tank. Using the cleaners is only a temporary solution until you can have the vehicle serviced by a professional.

Top off – To avoid a clogged fuel filter problem in a diesel tractor trailer, make sure to keep the diesel fuel topped off. This will prevent water condensation, bacteria and clogging in the fuel filter.

Replace the filter – When the fuel filter is fully clogged then the cleaners won’t be enough and it is time to replace it. In that case, it is best to replace the fuel filter rather than try to clean or rebuild it. If you have the knowledge to work on your own car, you can replace the clogged fuel filter with a new one. If you are not mechanically inclined, take your vehicle to a repair shop and have them replace the clogged fuel filter.

Check to see if you have a warranty on the old part. If you don’t have a warranty, you can buy another one. Fuel filters are not that expensive. However, your fuel filter may be difficult to get to. The labor will be a little more, but having it replaced will give you piece of mind. Note: When you have the clogged fuel filter replaced, have the technician cut the old filter open to see what type of activity was going on in it while it was inside in your vehicle.

Safety First

The fuel filter is not very big or sophisticated; however, it has a very big role to play in the fuel system. It is not safe to drive with a clogged fuel filter. The bad filter will cause more damage. You may get stranded when the engine will not start. Get that clogged fuel filter fixed, get back on the road, and drive safe.

Job Guthiri is a freelance writer with 3 years of experience writing for Motorsrun and other established automobile outlets. His focus and key interests are Tacomas and maintenance. Read our Editorial Guidlines and Fact Checking process.