Is It A Bad Fuel Filter? Here’s What To Look Out For.

by | Apr 10, 2020

Your fuel filter is exactly what it sounds like. It’s a filter that sits on your fuel line that prevents things like dirt and rust from getting into your engine.

If these contaminates do get into your engine, they can cause all kinds of issues. They can rapidly wear your fuel pump and fuel injectors, and severely diminish your car’s performance due to fuel not being burned correctly.

Your fuel filter needs to be replaced regularly. If you have an older car, you’ll probably need to replace it every 40,000 miles or so.

This doesn’t take into consideration the conditions you’re driving in. For example, if you live in a dusty area, you’ll need to replace your fuel filter more often on account of all the dust.

Today’s newer cars typically include the fuel filter as part of the fuel pump assembly – and you’ll need to replace it every 5 years or around 30-50k miles.

I recommend you check your owner’s manual for the specific service interval, as it does vary between makes.

This is especially important if you have a diesel-powered vehicle – as there’s fungus that can grow in diesel and then clog your filter, resulting in your fuel pump assembly blowing out.

That’s not what you want. The bill is certainly not pretty, coming in at somewhere between $400-$700.

So it pays to pay attention. Here are some signs that you may need to change your fuel filter.

So, How Do You Know If Your Fuel Filter Is Bad?

1: Difficulty Starting Your Car

If you had no idea your car even had a fuel filter until now, and you’re reasonably sure that you’ve never had it changed, then pay attention to how your car is starting. One of the first signs of a bad fuel filter is difficulty starting your car. A clogged fuel filter restricts the flow of fuel to your engine which can make your engine run lean because of lack of fuel.

2: Car Jerks When Going Uphill

When your fuel filter is clogged, gasoline won’t flow through the filter as efficiently which can cause your car to jerk when additional fuel is needed, such as well you’re driving uphill. A clogged fuel filter will make your fuel pump work harder under load, which can also lead to fuel pump damage. We’ll get to that in just a minute.

3: Burning More Fuel Than Usual

If your Toyota Corolla’s fuel consumption is starting to feel uncomfortably like a Hummer, then you may want to take a look at your fuel filter.

When your fuel filter is clogged, your engine can run lean, which will result in it wasting fuel as it works harder to keep your car moving. Changing your fuel filter can lessen the load and increase the mileage you’re getting.

4: Reduced Engine Power

If you notice a loss of power when your engine is under increased load, such as when you’re driving fast, your fuel filter may be to blame.

When your fuel filter is clogged, your engine’s demand for fuel can’t be adequately met by the supply coming from the tank because the fuel filter is clogged.

5: Engine Stalls While Idling

If your dirty fuel filter goes unaddressed for too long, it can cause your engine to stall. This could occur when the engine is placed under additional stress, such as when going uphill or when accelerating.

However, if you’ve ignored the clogged fuel filter, your engine could stall right after starting because of inadequate fuel making it to the engine.

6: Fuel Pump Failure

As I mentioned earlier, a bad fuel filter causes your fuel pump to work harder than it should.

And at the end of the day, I’ve got no problem with working hard.

However, if your fuel pump works too hard, it might decide that it needs a permanent vacation.

If your fuel pump decides to blow up, changing your fuel filter isn’t going to fix the problem. But hey, sometimes it’s good to know. Besides sending your fuel pump to the Bahamas, a clogged fuel filter can have other consequences.

A Bad Fuel Filter Can Cause a Car Not to Start

We get asked a lot if a bad fuel filter can cause a car not to start. The answer is yes – it absolutely can keep your car from starting. However, you need to really let your fuel filter get clogged for that to happen.

Again, your fuel filter is quite literally a screen. Enough gunk has to build upon it over time to completely restrict the flow of fuel to the engine. To get to that point, it has to be BAD

And when I mean bad, I mean worse than Walt on Breaking Bad.

That’s probably too controversial for this article – so I’ll leave it there.

If you have a diesel engine, sometimes your fuel filter can get completely clogged does on account of diesel fuel microbes and the black stinky gunk they produce.

What Does A Bad Fuel Filter Sound Like?

There are a few sounds your car might make that can alert you to a bad fuel filter. Because the fuel filter is just that – a filter, it won’t make any sounds on its own.

However, a clogged fuel filter can influence other parts of your car. By paying attention to these sounds, as well as looking at the other symptoms, you’ll be able to identify a bad fuel filter.

1: Straining Fuel Pump

When you turn your car on, it’s completely normal for your fuel pump to make a low humming noise while it runs. If you sit near the fuel tank and listen, you may be able to hear it when it’s running normally.

However, if the fuel pump is working overtime to compensate for a bad fuel filter, it will start to wear down. That’s when you know there’s a problem.

If you notice a loud whining or droning, your fuel pump is wearing out as it overheats from working too hard.

While it’s entirely possible that your fuel pump is just old, it’s also possible that a clogged fuel filter is causing the pump to wear out prematurely.

2: Sputtering Or Coughing Engine

If your engine sounds like it’s hacking out a lung, then it’s possible your fuel system is compromised on account of a bad fuel filter.

This should be especially noticeable as you accelerate to higher speeds and the demand on the engine increases.

On its own, a sputtering engine doesn’t necessarily mean your fuel filter is bad, as there may be other components in your engine or your fuel system that are causing the issue.

However, if you notice a sputtering sound in conjunction with some of the other issues I’ve mentioned, it’s worth it to have your fuel filter checked before your fuel pump decides to take a holiday.

3: Engine Misfires

If you notice your engine is misfiring when you’re accelerating, your fuel filter may be acting up.

When your fuel filter is clogged, the fuel supply to the engine will be diminished, which leads to less than the optimal amount of fuel being burned, which in turn causes misfires.

If you want to test this, try to smoothly accelerate on the highway up to 65 mph, and pay attention for the distinctive pop of an engine misfire.

An engine misfire on its own doesn’t mean that your fuel filter is bad. Any number of things could be wrong – so pay attention to the other symptoms on this list!

How to Check Your Fuel Filter

I’m going to be honest with you – if you have a newer car, checking your fuel filter is a pain in the ass. While many older cars have a fuel filter you can access from the engine compartment, most newer models have the fuel filter right next to the gas tank.

So if you read an article telling you it’s easy to check, you’re being bamboozled, unless you have an older car.

To change your fuel filter, you’ll either have to drop the fuel tank itself or hope you’re one of the lucky ones who can access the fuel tank from under the back seat.

If you’re reading this article, I’m going to assume you’re not a mechanic by trade.  

Your best bet is to take your car into the mechanic and have them check your fuel filter for you unless you have an older car that has the fuel filter in the engine compartment.

If that happens to describe you, check out this great ChrisFix video which can help you change it out.  

How Much Does A Clogged Fuel Filter Cost?

The fuel filter itself is inexpensive. It’s quite literally a piece of paper in a metal or composite housing. Depending on the fuel filter your car takes, a new fuel filter can cost you anywhere between $20-$50 dollars.

On average, it’s about $35 across nearly $1 billion in claims that we’ve processed.

However, as previously mentioned, it’s a pain in the ass to replace your fuel filter yourself on a newer car. So, if you take your car to the mechanic it shouldn’t take more than 30 minutes to fix your fuel filter.

That will leave you with somewhere between $40-$60 dollars in labor, assuming it’s just the fuel filter you’re changing out.

Total cost: $85 or so.

Worried A Bad Fuel Filter Will Destroy Your Fuel Pump?

A fuel pump repair can cost upwards of $500 dollars, which can be a major hit to your wallet.

If you’ve had a bad fuel filter in your car for too long, it’s possible that your fuel pump or fuel pump assembly may have been weakened to the point where it’s almost dead.

And that’s the last thing you want.

Fortunately, if you have a vehicle service contract with Protect My Car, if your fuel pump does decide to quit, we’ll step in and pay for the entire cost of the repair with no out of pocket cost to you

All of our policy options cover your fuel pump, including our Ambassador line, which covers older vehicles with up to 300,000 miles.

If you want to learn more about how effortless it can be to drive with a vehicle service contract from Protect My Car, request a quote below and we’ll show you just how great your driving experience can be.

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