Heels & Horsepower Magazine


Types of Car Filters and Their Purpose: A Quick Look at the Humble Fuel Filter

by H&h Admin

There are four main types of filters in every car; the cabin filter, fuel filter, oil filter and air filter. In this article, we talk about the importance of the fuel filter.

When fuel comes out of a refinery, it’s clean but when it is poured into fuel carriers as well as the pumps at the fuel stations, it may become contaminated.  What this means is that there is a very high probability that the fuel poured into your tank contains a few contaminantes.  

So, what is a fuel filter and what does it do?

Think of the fuel filter (and other filters) like a sieve, similar to the one in your kitchen.  Imagine you are straining pulp after squeezing the juice from an orange juice. All the debris remains in the sieve and only the pure orange juice flows through the sieve. Similarly, a fuel filter works in the same way.

Located within the fuel line, a fuel filter is a cartridge with a screen within it.  The screen catches the dirt and other debris which may pour into your fuel tank along with the fuel.  As in the example of the orange juice, the fuel filter ensures that only the fuel passes through the filter and enters the car’s fuel line. 

Thanks to the correct fitment of a good quality fuel filter, the fuel going through your car’s fuel line is generally free of dirt and other pollutants which would otherwise damage your fuel system.

Signs your fuel filter needs replacement

Let’s go back to the orange juice example. After pouring pulp through the sieve for a while, the sieve gets clogged up, making it more difficult for the orange juice to pass through it.  In the same way, the fuel filter also gets clogged up over time and needs to be replaced.  Failure to change a blocked fuel filter can lead to noticeable problems to your otherwise smooth driving experience.  

Image: AutoZone

Here are two common problems you may notice when your fuel filter is taking strain: 

1. Poor engine performance

A blocked fuel filter causes the engine to sputter or hesitate randomly. This can happen at any time but is more prominent when accelerating or when traveling up a steep incline.  A clogged fuel filter limits the amount of fuel going through the fuel line, drastically reducing the car’s ability to perform optimally.

2. Stalling or misfiring 

An engine that repeatedly stalls while driving could be a sign of a dirty fuel filter.  Depending on the severity of the blockage, your car may start right back up without any noticeable loss of power.  However, as the clog worsens and fuel delivery becomes more sporadic, stalling will become more excessive or worsen upon acceleration.  Worst case scenario, your engine will stall and fail to start up altogether.

Keeping up with fuel filter maintenance

Following the recommended change intervals in your owner’s manual is key to maintain optimal vehicle health, and in this case, the health of your fuel system. Waiting until you are starting to experience issues with your fuel filter may cause bigger fuel delivery issues to deal with beyond a clogged filter. 

Impurities that pass through the fuel filter can cause a fuel injector to leak which in turn can lead to a myriad of drivability problems.  Replacing a dirty fuel filter is a relatively inexpensive and easy fix and once attended to, you should be back on the road in no time!

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