Fuel water filter warning - help

[noblewilson]

I had the fuel water filter warning light on, so I replaced the fuel filter, fired it up again, but the warning light still stays on! Also, it does not start particularly well, (didn't before either) needing to be turned over quite a lot before it picks up. Any ideas would be appreciated.

Noble

[Hazzo]

you can just drain the water by using the cock/tap underneath the filter, but as you've changed it out have you pumped/primed the plunger till its hard, meaning full of fuel n ready to rock. H

[noblewilson]

Fuel filter primed

Yes, I have fully primed the filter and there can be no residue water as I replaced the filter, so don't understand why the light should still be on!

[NiftyNev]

so don't understand why the light should still be on!

Drain some more fuel and check it. You could have more water in there.

Nev

[noblewilson]

Tried draining some more, still no different, could it just be a dodgy switch? Also if this light is on, does it go into 2limp mode"?

Noble

[NiftyNev]

If there is no water in the fuel you drained unplug it but do check for water every now and then. If you get a batch of dodgy fuel with water in it it will be very bad for the pump and injectors. I suggest you fix it at the next filter change or sooner if you can. It's just a warning light and won't have any affect on engine operation.

Nev

[RickB]

Check to see if the float inside has stuck in the upper position, thus falsely indicating water contamination, or check to see if the wiring has shorted out. I had a sensor which had done this...

[noblewilson]

Rick,

Seemed like good ideas, but I have replaced the sensor with float and still got the same problem!! Not sure what to try next.

Noble

[RickB]

Hi mate
If you have changed the sensor and checked that isn't water in the system then I would suggest that the loom has a short in it. Unplug the sensor plug and check the two terminals on the sensor side with a multimeter set to ohms. If the float is in the lower position (as it should for zero water content) then your reading should be infinite(open circuit) then check the other connector on the loom. If this shows a low resistance reading then you have a short circuit in the loom giving you a false contamination reading. Just a case of following the wires back to see where the insulation has melted or chafed to give the short.

Rick

[noblewilson]

Rick,

Thanks for that, I'll give it a go.

Noble

[noblewilson]

Rick

It was a faulty reading, but caused by a dodgy alternator! Replaced it and everything is fine.

Thanks,

Noble

[blackpoolsparks]

glad to hear you resolved the issue.
I didnt even know there was such a sensor.

Can someone enlighten me as to how one would come to have water in their fuel system

[MattF]

glad to hear you resolved the issue.
I didnt even know there was such a sensor.

The wires to that big plug on the bottom of the fuel filter are the usual giveaway.

Can someone enlighten me as to how one would come to have water in their fuel system

Water getting in through the tank breather if doing a water crossing and the filter is missing or shagged, or even just the simple fact that diesel does absorb moisture over time.

[the silver surfer]

This sounds distinctly like the issue I'm having right now. Where is the tank breather as I drive through a river nearly every day here.

[NiftyNev]

Breather on the 3rd generation (and on previous models as far as I know) is located high up on the filler neck, so not an issue, unless the water is that deep. If it is you got bigger worries.

Nev