What Does the Fuel Filter Warning Light Mean? | YourMechanic Advice

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.


Schedule Warning Light is on Inspection
Service Area

$79.99 - $89.99

Price range for all vehicles
Average rating from 170 customers who received a Warning Light is on Inspection.

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

Excellent Auto Repair Ratings.

4.2 Average Rating

Auto Repair

Service Hours

7 AM - 9 PM

7 days a week

Phone Number

Phone Hours

Mon - Fri / 6 AM - 5 PM PST

Sat - Sun / 7 AM - 4 PM PST

Address

We come to you at no extra charge

Guarantee

12-month/12,000-mile warranty

Service Area

Recent Warning Light is on Inspection reviews

Excellent Rating


YourMechanic Warning Light is on Inspection Service

Average Rating

4.9/5

Number of Reviews

170

Rating Summary
160
3
4
0
3
160
3
4
0
3

Travis

12 years of experience
425 reviews
Travis
12 years of experience
Volkswagen Beetle - Warning Light is on - Stillwater, Minnesota
Unbenoest to me when you change a battery on a 18 yr. old car you also need more than a code reader to reset the new battery.
Audi A8 Quattro - Warning Light is on Inspection - Minneapolis, Minnesota
Very helpful and very knowledgeable will be using this service again thank you Travis for everything trumbs up

Nicholas

10 years of experience
361 reviews
Nicholas
10 years of experience
Chrysler 300 - Warning Light is on - Durham, North Carolina
Excellent diagnostician. Knowledgeable and caring. Created a desire for him specifically, to do the job. Hope we get him every time!
Honda Accord - Warning Light is on - Garner, North Carolina
I was very happy with Nicholas and his knowledge and expertise about diagnosing the issues with my car. He is honest, reliable and professional. He is now my Mechanic that I will call on for all my car's needs.I will also recommend him to my friends whom have been taken advantage of by other car shops as I have been, and are looking for someone honest , that will not take advantage of them Thank you so much Nicholas for resolving my issue with my car. I feel relieved and happy with the outcome

Robert

15 years of experience
24 reviews
Robert
15 years of experience
Chrysler 300 - Warning Light is on - Maricopa, Arizona
Very professional, knowledgeable. Explain everything in great detail. Will definitely use Robert again.

Arturo

26 years of experience
183 reviews
Arturo
26 years of experience
Volvo XC90 - Warning Light is on - El Cajon, California
Arturo was very professional and friendly. Diagnosed my problem immediately, and I feel confident the service will be to my satisfaction when my radiator arrives for installation.

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