Is my Fiat 500 Multijet suffering from a DPF fault?

I purchased my Fiat 500 diesel Multijet in April this year. It's about five years old. According to the service history, the oil was changed in October last year. The flashing oil light came on in May, so I had another oil and filter change. Now it's October and the light has come on again. The text says “change engine oil”. Why is this happening? Do I need to change the Diesel Particulate Filter? My dealer recommends I get a full service done, but I think they're just ripping me off.

Asked on 21 December 2013 by TT, via email

Answered by Honest John
It's happening because too much extra diesel is being injected into the engine to fire off the soot in the DPF, so the extra fuel sinks to the sump, contaminating the sump oil. Leave it too long and the sump level will rise to a point where the engine runs uncontrollably on its sump oil and can only be stopped by force-stalling it. Numerous 500 Multijets have blown up for this reason. In Mazdas, the ECU needs to be re-set following an oil service or it will continue to add excess fuel to clear the DPF whether the DPF needs it or not, so maybe the same happens with the 1.3 Multijet.
Tags: dpf oil diesels ecu
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