Water in fuel after draining and filter replacement

[turtle]

2023 JT Sport S diesel. 27K miles. Around 25k miles (after 3 dealer oil changes), I started seeing "water in fuel" warning. Drained the fuel filter (didn't see any water), but it continued.

So I replaced the fuel filter and it stopped for a few hundred miles, but the warning message is back again and my mileage is crap. Drained the water separator again but message remains. Also, the first crank after it sits for a few hours is rough, sometimes doesn't start immediately.

It only shows up when I start the engine, then the warning light goes away after a few seconds.

Any suggestions on what to try before I take it to a dealer?

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[Primer Gray]

I’m experiencing the exact same thing.

Drained the filter housing a number of times, changed the filter twice — and am still getting random water in fuel message on the dash.

 

[Rusty PW]

When you remove the fuel filter. There are 2 probes that stick down in the center of the filter. That is your water sensor. You might want to wipe them off and clean them. See if that helps.

 

[turtle]

When you remove the fuel filter. There are 2 probes that stick down in the center of the filter. That is your water sensor. You might want to wipe them off and clean them. See if that helps.

Thank you. I will try that soon.

 

[DylanM]

FWIW, I started getting a rash of "water in fuel" messages on startup around this time last year. Like you, when draining the separator there was no evidence of any water, changing the filter seemed to make no difference, and the warning would go away if I shut the engine off and restarted it again. The messages stopped popping up after both batteries in the truck were replaced (I had also been getting "Engine stop/start not ready" and random "Auxiliary switches unavailable" messages for a couple months prior). You might want to check on the health of your batteries as what appeared to be false water in fuel messages seemed to be associated.

 

[Lost1wing]

I do not have a diesel JT! However, on other diesels, I have seen "water in fuel" and "fuel filter 0% ", right when the temperature drops below 32f. Most of the time I would find the filter housing sucking air. Replacing the fuel filter usually takes care of it. I have also found primers bad causing it suck air when shut off. These seals shrink a bit when cold and if not installed correctly, it could cause problems later down the road. This happened to me only one time after a fuel filter change. It was 85f when I replaced the filter. A week later on a trip the temps dropped to 0f. The truck did not start. I got the water in fuel and 0% remaining message. I did find fuel had been leaking at the filter. The oring did not seal after trying to tighten. Replacing with a new warm oring that came with a new filter was what I ended up doing. Not fun at 0f, in a parking lot.

Cleaning the probes off is a good idea too as was mentioned.

Diesel no starts and hard starts followed by running rough is a sign of fuel starvation, loss of prime. You can verify your fuel pressure if you have a scan tool.

 

[Primer Gray]

FWIW, I started getting a rash of "water in fuel" messages on startup around this time last year. Like you, when draining the separator there was no evidence of any water, changing the filter seemed to make no difference, and the warning would go away if I shut the engine off and restarted it again. The messages stopped popping up after both batteries in the truck were replaced (I had also been getting "Engine stop/start not ready" and random "Auxiliary switches unavailable" messages for a couple months prior). You might want to check on the health of your batteries as what appeared to be false water in fuel messages seemed to be associated.

Bingo.

Replaced both batteries and the issue has not re-emerged over the past week.

Thanks, as this probably saved me from getting stranded with a battery failure.

 

[turtle]

So, a resolution. Short version: It was the main battery. Replaced under warranty.

I had the battery tested twice and it passed both times (local garage and Autozone). However, Monday morning I tried to start the Glad to go to work and it would not start. It would crank one time, then stop. Battery meter on the dash was 12.2v-12.5v. I was able to start it with a jump pack.

I already had an appointment with the dealership to diagnose this since the truck is pushing 30K miles and I hoped to get something out of the warranty before it's gone.

They used some "much more thorough" piece of machinery "provided by the manufacturer" to diagnose a failing main battery. Auxiliary is supposedly fine. I assumed I would bear some part of the cost of the battery, since it's often considered a consumable. However, it cost me nothing (except a day without the truck), so no complaints.

 

[JeepDaddyJT]

had same issue - cause was low battery voltage --- replace the small battery as well as the main battery

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