Aug 23, 2022 at 8:56 AM
  1. TDRComm Staff Member


    Let’s cut to the chase: If the water-in-fuel light comes on the first thing to do is to stop driving the truck.

    Repeat, STOP driving the truck. Chances are you aren’t too far from the fuel island where you just filled the tank? (Our guess, about one mile away from the fuel stop.)

    Now, if we can’t correct this problem with the following common-sense procedure, you’re going to want to get some documentation about the cause of the problem:
    • Fuel receipt
    • Date stamp of you and the truck at your new-found, temporary roadside service location
    • A photo of the fuel stop
    • A photo of the water-in-fuel light;
    • A conversation with the store manager; you know the routine. Later you’ll have a chance to take a picture of the contamination.
    We’ve heard from TDR members that some of the “800-HELP ME PLEASE” phone numbers at the major fuel retailers are very helpful and will reimburse for filters and such. We’ve not heard “the rest of the story” when the owner continued to drive and contaminated the expensive fuel injection system.

    So, let’s not make this into a big deal. Water and diesel fuel don’t mix.

    Now: Let's get busy fixing this problem:

    No Need to Panic

    Logically thinking: If your truck is 2013 or newer Turbo Diesel, it has two fuel filters, the chassis mounted and the engine mounted filters. Closest to the fuel tank, the chassis mounted filter’s sensor was (99% certainty) the trigger for the water-in-fuel light (WIF). The repair procedure: Grab that empty, clear, water bottle from your cup holder; crawl underneath the truck; open the fuel drain valve and see what comes out.

    Round Two

    Got it all? Observe how quickly the water and fuel separate in your bottle.

    Feel confident? Let’s purge the chassis mounted filter again. Close the fuel drain valve. Turn the ignition to the “on” position. Listen for the fuel pumps to operate (a slight “buzz” noise). It will shut off in approximately 20 seconds. Open the drain valve and catch the fluid in the water bottle.

    Got it all? Any water?

    Feel confident? Use the ignition-on to reprime the chassis mounted fuel filter and purge again just to be sure.

    At this time (if you have a spare) replace the chassis-mounted filter.

    Needs Further Attention

    By now chances are you’ve solved the water-in-fuel problem. As an extra precaution, you can also drain the fuel filter at the engine. This filter has a lever or knob that opens the fuel filter housing to let the liquid (still 100% diesel fuel, we hope) drain down the fuel tube.


    However (you knew “however” was coming), the factory folks didn’t provide a lengthy drain hose. So, you are going to get your backside dirty as you crawl under the engine to put that water bottle in the proximity of the drain hose.

    Open the knob, have someone turn the ignition “on,” listen for the fuel pump to operate for 20 seconds. Capture the fluid from the drain hose (what a mess) and check for water.

    Repeat as needed.

    Close the drain knob.

    Vow to purchase a hose to extend the factory drain line at the engine mounted fuel filter. Purchase some 3/8” clear, vinyl hose at the hardware store. It will slip over the existing drain hose with a slight interference fit.

    This technique should get you back on the road. However, don’t be too surprised if you have to go another round (or two) with the WIF light and the chassis mounted fuel filter drain technique. Logically, the water is at the bottom of the fuel tank. But logic doesn’t always win the fight with a knockout in the first round, second, or even the third round. You may be chasing the contamination for several days...

    Scott Sinkinson
    Senior Tech Support/Diesel Guru at Geno's Garage
    (Scott is also often the guy if its going to happen, it'll happen to his truck)






    Last edited: Aug 23, 2022
    TDRComm , Aug 23, 2022


Discussion in 'Articles' started by TDRComm, Aug 23, 2022.

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