Skip the auto shop - Our mechanics make house calls

What Does the Fuel Filter Warning Light Mean?

What Does the Fuel Filter Warning Light Mean?

Diesel engines are quite different from their gasoline counterparts. Besides not using spark plugs, just about every diesel engine uses fuel to lubricate high-precision engine components. Unfortunately, trace amounts of water can be found in diesel fuel and it needs to be removed before it gets to the engine.

Water doesn’t work very well as a lubricant and it could cause excessive wear on the engine if it made its way through the fuel system. To prevent this, diesel fuel filters are designed to separate the fuel and water before it heads to the engine. The water is collected and must be emptied out occasionally, otherwise it will start to pull through the filter and make its way to the engine.

Some vehicles may empty the water automatically or you may have to empty it manually. A warning indicator on the dash will let you know when too much water has been collected and the fuel filter needs to be emptied.

What the fuel filter warning light means

Inside the fuel filter is a fluid level sensor that keeps track of the amount of water that has been collected. Once the level starts reaching maximum capacity, the fuel filter warning light will illuminate to let you know to empty the filter.

On manual systems, a valve at the bottom of the filter will let the water drain out once opened. If your filter empties automatically and the light comes on, it indicates that an error or malfunction has been detected and it needs to be checked out as soon as possible. This warning light could mean that the drain is blocked and the system can’t empty itself. A code will be saved on the computer to help you identify the cause of the problem. Have the car checked out with diagnostic scan tool to find the saved code or codes.

Don’t ignore this warning light or the system will fill with water and start leaking it to the engine. Once the water has been drained from the filter, this warning light should go out on its own.

Is it safe to drive with the fuel filter warning light on?

While it’s not an emergency when the light first comes on, it is important that you get the filter drained as soon as possible. Waiting too long will let the water build up and eventually let it get to your engine where it can cause some serious damage. Remember to change out the fuel filter at the right service intervals as draining the water will not remove all the particulates that are caught in the filter.

Our certified technicians are always available to assist you in diagnosing any problems with your car’s fuel filter and they can drain or replace your fuel filter for you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...


Related questions

Q: What other parts do I need to have besides the throttle body and the gasket? I have already purchased both items.

Hi and thanks for contacting Your Mechanic. Before you replace any parts, get a fuel pressure tester and test the fuel rail for pressure. There should be 35 psi or more on the rail for the engine to run. If...

Q: Warning lights on

The ABS light and brake lights indicate that there are faults stored in the Electronic Brake Control Module or EBCM. These faults need to be read out to determine the issues in the ABS system. Now it could be something...

Q: Trouble starting and acceleration bogs down

Hello there, thank you for asking about your 1986 GMC S15. You don't say whether you have an automatic or manual transmission, so I'm not sure how to help you with your shifting concern. As far as the engine performance...