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 Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...


Related questions

Q: fuel filter

Hello. We will be happy to assist you. There are are a few things that I recommend a technician inspect. Fuel should have been inside the filter once you removed it. A test must be done to see if the...

Q: What does the AdvanceTrac off Warning Light mean?

The AdvanceTrac off Warning Light is located on the instrument panel. This light illuminates when you have manually turned off the AdvanceTrac traction control system. When you turn the system back on, the light will disappear. Tip The AdvanceTrac off...

Q: Car stalls, hesitates, misfires - 1998 Oldsmobile Delta 88

There are several potential problem areas (besides fuel supply which you seem to have addressed), which could cause lean running and the symptoms you describe. A dirty throttle body, failing mass air flow sensor, vacuum leak, or bad oxygen sensor...