I've just started up my van (ducato 120 multijet) and, while engine running, the 'Water in diesel fuel filter' warning light stayed on. What do I need to do to sort it out?
The van is a 2009

if you're lucky there will be a drain on the bottom of filter housing ( un-plug wires if any) just twist it to drain water out

I can't understand how water could have into the fuel. It's only done 11000 miles.

??? Not put the petrol cap on fully, and with all this rain ! It doesn't take much! Or contamination at the petrol station!

condensation

If I manage to get the filter apart, clean it, and replace the element, will the filter housing need bleeding?

Hi
Check out my previous thread on changing the fuel filter on a 2.8JTD Ducato,
you will find that your 120 multijet is basically the same procedure except yours is not a spin-on type that most of the 2.8 JTD engines used. The last of the 2.8 JTDs went to the cartridge type the same as the X250 models, but the bleeding procedure is the same.

https://www.fiatforum.com/ducato/142975-how-change-fuel-filter-2-8jtd.html

You do not need to take the filter apart.

Any space in the fuel tank above the fuel level will be air. This will contain moisture, as does the air around us. When the temperature is cold, the moisture condenses on the sides of the tank, and drains down into the fuel. The fuel rises above the water, so some water is drawn forward to the filter, which is designed to separate it out. When the water volume gets to a certain level, the light comes on to tell you that you should have drained it more frequently. There will be a tap on the bottom of the filter to drain the water out. Anything drained out should be disposed of properly. Not down a drain, or onto the compost heap, etc, but taken to a garage to add to their waste oil is the best idea. (How many people do that?) Your handbook will advise on location of drain, and how.

Petrol vehicles also get condensation, but the water gets pushed through with the fuel and just reduces the power a little. Less of an issue. The diesel filter has to separate it as the injectors and high pressure pump rely on the fuel as a lubricant.

Ideally, all diesel vehicles should have their tank filled to the brim before every cold night. Bus companies are good at this, as they have the facilities and routines. Many large hauliers can do so too, but a pain to individual vehicle owners.

This problem also occurs in the storage tanks at garages, although less so as they are underground tanks and their temperature is more consistent. Good filling stations will regularly dip the tank with some water identifying paste on the bottom of the dipstick and water is pumped out. The fuel delivered to your car at garages is taken from the tank a little above the bottom, so you can never get the last of it out via the pumps.

chilly500 said:

If I manage to get the filter apart, clean it, and replace the element, will the filter housing need bleeding?

Click to expand...

No, turn the key to first position until the pump turns of, repeat until you hear no more bubbles/cavitation in the tank.

Theres probably a grey drain screw angled down the side and a drain at the bottom. But change it anyway even if you've drained it.

Thanks for all your advice. I drained the filter and the light went out after a few seconds. Tried it about ten minutes later and the light stayed on so I thought it might be a dodgy connection at sensor. Took it to a local garage who drained the filter again light came on again. Waited a couple of minutes and the light went out. Brimmed the tank and then drained filter again. light came on for a few seconds. I then took it for a good 7 mile run with light off. Light now staying off on start up.

Do you think it might now be sorted Nigel?

I need to use it tonight (thursday) will it be safe as long as the light is off?

chilly500 said:

Thanks for all your advice. I drained the filter and the light went out after a few seconds. Tried it about ten minutes later and the light stayed on so I thought it might be a dodgy connection at sensor. Took it to a local garage who drained the filter again light came on again. Waited a couple of minutes and the light went out. Brimmed the tank and then drained filter again. light came on for a few seconds. I then took it for a good 7 mile run with light off. Light now staying off on start up.

Do you think it might now be sorted Nigel?

I need to use it tonight (thursday) will it be safe as long as the light is off?

Click to expand...

If its that much water it sounds like you got a very bad fill. Do you know where you filled up last, I'd go back there report it to them and get a sample in case you have problems in the future. Always keep the receipts so you can remember. No filter has perfect water seperation and theres only the lubricity of diesel between the metal parts and up to 25000 pounds per square inch of pressure in common rail. If it was me I'd at least lift out the sender and see whats in the bottom of the tank but then that wouldn't cost me anything except 15 minutes of my time .

Moodrater's advice is all good.

If you have had a few cold nights, with the fuel level low in the tank, this could cause a lot of condensation. With the tank now brimmed, any condensation on the tank walls will be washed down, to settle at the bottom overnight. This may therefore draw through a lot on next use, but then should be sorted. So whilst a bit of a pain, shouldn't be a big issue. If you're due a cold night, especially after a warm or damp day, best to fill the tank if you can.

Now what we really need is a tank liner like wine in a box, where the bag collapses as the wine is drawn off.

I recently purchased a 1.3 multijet Doblo (2008). After the first fill and several hundred miles later the water in diesel light came on. I drained the filter and the light went out. A hundred miles later the light came on again. I drained it a second time but the light wouldn't go out so I replaced the filter. The lights still on so I assume a faulty sender. Problem is this leaves me exposed should the filter start to fill up with water as I wont know if its spurious or real.

Anyone else have similar problems?

Four weeks later and the water in diesel light still makes random appearances. Its either on when you start the engine or its not but there appears to be no pattern.

In a Ducato the water sensor is part of the UFI fuel filter housing.
Once water has filled the cavity there is rapid bacterial growth leaving a slimy residue that may impair the sensor function. To restore proper operation remove the filter housing, flush it with warm water and some detergent, let it dry completely, then reassemble it and install it in your vehicle.