Isuzu D-Max Fuel Filter Problems

Isuzu D-Max truck, 2012 model

The latest Isuzu D-Max truck. I bet it has fuel filter problems too!

We bought one of the new series Isuzu D-Max trucks in September 2012.  It’s been excellent so far apart from one thing.  The fuel filter has needed changing twice so far, and it has only done 10,000 miles!

We’re preparing an in-depth review of our Isuzu D-Max Utah truck, so you’ll see how good we think it is when we publish that article. The truck has been very reliable so far, but we have encountered issues with the fuel filter warning light coming on.

The truck had only done 8,000 miles when the issued raised its ugly head. The amber fuel filter warning light started to come on intermittently at first. We thought it may have been faulty so it was ignored for a while. It was only when the light was on most of the time that I contacted our dealer – Roger Young in Saltash, Cornwall – to see if there really was a problem.

With their usual efficiency, they booked the truck in for a filter change straight away, so I took it in expecting it to be fixed under warranty. With the Isuzu being so new, I thought that the problem must have been caused by a faulty filter or something like that.

No, the technician at Roger Young changed the filter and then patiently explained that it had been working properly and that we must have filled the vehicle with contaminated diesel, maybe even from our own storage tank (we don’t have one!). It therefore wasn’t covered under warranty, as it was a problem that we had caused.

Reluctantly, I paid for the repair and vowed to only fill the truck up at busy petrol stations, which are not likely to run their diesel tanks dry, possibly allowing sludge to be dispensed with the fuel.

That was four weeks ago.

You’ve guessed it, the fuel warning light has started to go on again. As before, it started intermittently, but is now on for most of the time. Time to contact Roger Young again, but this time I was determined to sort this out under warranty as there is something clearly wrong either with the filter or the warning control system.

Well, it turns out that there is a problem that Isuzu know about. Apparently the filter is too fine so it filters out more than it needs to and gets clogged up far too easily. Isuzu are covering the problem under warranty.

So the vehicle is booked into Roger Youngs again. They can only replace the fuel filter with the same model that has the inherent problems, so it is only a short term fix, however they are speaking to other dealers to see if they have found a more permanent solution.

Hopefully, Isuzu have set the wheels in motion to redesign the fuel filter so that this issue is fixed once and for all.

So if you have one of the excellent Isuzu D-Max trucks and you get that dreaded fuel filter warning light coming on, don’t be talked into paying for a replacement. Isuzu are accepting that this is covered by warranty.

I’ll update this post when we get the filter replaced, and when we know what the long term fix is. In the meantime, feel free to post a comment below about your experiences with these faulty filters.

Important Update 16 March 2013

Our Isuzu D-Max has now had its first service and the fuel filter issue has been rectified permanently (hopefully) under warranty.

Isuzu have investigated the problem and found that the high bio diesel content in UK fuel increases the viscosity of diesel and reduces the flow through the filter, triggering the warning light.

This is fixed by the dealer replacing the whole filter assembly which now warms the diesel up to 55 degrees as it passes through the system, thereby reducing the viscosity of the fuel and increasing its flow rate.

Apparently this is affecting Isuzu trucks and lorries too.

So if this is happening to your Isuzu, get the fuel filter assembly replaced under warranty as soon as possible.

11 Responses to “ “Isuzu D-Max Fuel Filter Problems”

  1. Stuart Allan says:

    I have had three fuel filters and one filter housing on my veichle and it has only done just over 7000 miles I got the vehicle end of October 2012.

    I have got my all done under warranty though there was a bit discussion around the first one I was told it was contaminated fuel that was causing the problem but I have a Peugeot car and it runs on the same fuel (Morrisons supermarket) and it was giving me no bother.

    The first couple of times my fuel light came on there was others as well and the vehicle was going into limp mode quite often.

    • Diane says:

      Hi Stuart.

      Thanks for you comment. Make sure that your dealer changes the whole filter assembly with the new one, as Roger Young have done to ours.

      • Stuart Allan says:

        My fourth fuel filter is now starting to give problems only if the engine is running hard or having to do something My veihcle has only done 9000 miles Latest story I heard from Isuzu they think is the amount of Bio Fuel there is in the fuel that is causing the problems The dealership I use are also Ford dealers as well and they were telling me that they are aso getting the same fuel filter issues with Transits

  2. Roger Norton says:

    Hi
    Just had my Utah back from 12K service.
    Fuel filter replaced at 4700 miles and now back on again.
    Dealer contacted Isuzu and confirmed there is a fix, it is a modified filter assembly and will cure the problem (allegedly)
    When I use the truck with English fuel there is no problem, its only after 2-3 refills in Scotland that it comes back on, apparently the Scots have a higher bio content in their fuel.

  3. Lorenzo Lamatti says:

    im using isuzu dmax 2.5d intercooler basic model.
    almost brand new with 13.500km
    the last few days, the amber fuel warning light appeared permanently, but only after 2000 RPM
    is the warning light looks like a tank station logo and points underneath?

  4. Lorenzo Lamatti says:

    ok, i’ve started to use a new type of diesel. the better one.
    now the warning light is only after 3000rpm, and less times, than it was before with the ‘cheapest’ diesel.
    So i say yes, problem solved.
    my only problem is that with a full tank i can go 650, max.700 km.
    isnt it too low?

  5. Kristen Taylor says:

    My Dmax in Australia, not even 2 months after having buying it new, had the water seperator light come on, called the dealer 2 times, told not to worry about it. Third time the light came on, took it back to the Dealer & was told it was water in the filter, charged me as not under warranty with dirty fuel. Been exceptionally cautious since then. Two weeks ago the vehicle wouldnt start, taken back to Dealer as still under warranty, fixed it, said was the suction valve. Same problem the other day, ignition would turn over but not start. Back to the Dealer & informed needs $12,000AUD in repairs as rusty water in the filter. My question is why did the water seperator light not warn me? And why did the Dealer that specialises in this vehicle not run the necessary checks when issues first presented themselves. Any advice appreciated

  6. Paul Tibbles says:

    Thanks for all the information. My filter light comes on when the vehicle is pressed hard. Stripped the filter out last night, looks perfectly clean (9,000 miles) only used Esso fuel from new (Sept 2012). I will ring the dealer in the morning after, and report back.

  7. chris Hardy says:

    Now on my 4th Fuel Filter after 12000 miles and warranty rejected on the basis that we have not been using the vehicle enough, supermarket fuel, warm weather, wet weather etc etc!! £93 to supply and fit the filter so in 120000 miles (our anticipated vehicle lifetime) it will need 30 filters or £2790 on them not including inflation etc. My Land cruiser has had 1 filter in 50000 miles and that was routine service item. Wish I’d bought a Hilux!!

  8. russell says:

    had two filters two housings. isuzu is rubbish next problem is fuel getting into oil all Isuzu seem to do is oh there is an upgrade for that .mine has had a rattle on engine been back to dealer more times than I care to remember for the same problem all I get is bull **** back. poor fuel economy crap dealer service .as mine broke down twice in first 6 mths it was one of first in country only to be told we don’t have the software for it by two dealers ,joke wish id bought another navara cant wait to get rid hope Isuzu uk read these posts few lessons need to be learned before you launch a car sort the niggles out first .

  9. David Walter says:

    My fuel filter was changed under warranty at 25000 miles. Just done over 60000 and no more problems.

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