General DPF Issue on Fiat Multipla 1.9 multijet

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General DPF Issue on Fiat Multipla 1.9 multijet

Hulk83

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Hi,

I have a Fiat multijet 1.9 and have been having some issues with the clogged filter so engine management light has come on several occasions.

local garage has done forced regen a few times however last one did not work. I bought Wynn particulate filter cleaner and this resolved the problem after several days.

However i think there is a problem with the regen activation itself on the car. - The glow plugs light flash so need changing. Is this linked to the regen please?

Engine management is on again and have put wynn cleaner in yet again. any help would be much appreciated.
 
Hi - can someone help me out of this issue please?

Many thanks
 
I can't see the glow plugs being the problem - I suppose slow starting might mean a little more soot going down the exhaust, but not enough to explain dpf problems.

Mine alarms/warning light about every 3 months as I only use the car for a short commute. Occasionally it tries to do a regen if I go further afield. A cruise along the M4 to London works nicely (it usually goes into regen around Reading), but sometimes it decides to try one when I'm only gone a few miles up the M5. I can hear it trying to regen in queues. Fuel consumption shoots up, and engine sounds really rough. You can tell it is doing it if you put the data on "Range" as it tracks mpg every few seconds.

I 'fixed' the problem by buying AlfaOBD and installing it on a 7" tablet I use for work. Software cost about £35 - I imagine one trip to the garage would cover that? When the engine light comes on, I run a forced regen myself usually somewhere remote as it is a noisy process.

I have monitored the process (using the AlfaOBD) and the forced regen definitely works best if the engine has barely warmed up. It will get the dpf to 700 Celcius, and the pressure reading drops back to 5mbar (i.e. the filter is clear). Once the cycle is over, I drive home in 2nd gear at about 3600 rpm as the dpf is still hot enough to burn off the soot.

Running a regen when the engine is hot, I find I usually have to do it twice. No idea why, but the temperature only gets up to 400 Celcius.

One last thing - the condition of the oil is part of the computer's decision making process as a regen messes up the oil (I think it dumps raw diesel into the cylinders at the wrong time so that unburnt fuel gets down to the filter). If you do an oil change, you'll need software and an OBD link to tell the control system you have done it.

When I got the car from my brother in law, it was on 100K, and the oil change procedure had not been run since 26K, despite him using 'proper' garages. This causes the oil light to flash for about 30 seconds after start up (presumably to tell you that as you haven't changed the oil for ages, it won't be doing a regen any time soon). Seeing the oil light flashing, he took it in. The mechanic charged him cash (basically to check the oil level and look for leaks), and never thought of Googling "flashing oil light multipla".

Anyway, to sum up...buy AlfaOBD plus OBD link (or similar). Take car for short drive. Read codes (I think 1206 is the one you are looking for). Clear codes. Run "regeneration". Change oil. Run "oil change" procedure. Always take device plus link if going away for a few days.
 
Indeed - just in case you missed it in my long story, I repeat, read the codes first and check it matches expectations before doing a "burn" as we know it in our house.

The forced regen cycle on the AlfaOBD software does repeats the warning.

Fact is, dpf regeneration is recognised by a lot of engineers as being a bit like the chain on a bike. A desperately bad, clunky solution to a problem, but works until we think of something better.

I understand all sorts of alternatives were considered including electrostatic precipitators at one point!
 
Hi all

Thanks for your replies.

I have had my car plugged in the machine a few times and it came up with the particulate filter blocked.

I managed to clear it and run a regen down to 16% before but 2 weeks later the engine control light came back on putting car in limp mode.

I have had the oil changed and removed the error code.

The only other code that flashed up at the time was PO683 which i believe is the glow plugs.

Today I have asked a friend who is a mechanic to change the glow plugs as necessary and doing another regen.

I admit the car doesnt do long journeys regularly but surely shouldnt block up that quickly. I am told that if there is error codes it wont regen.

Dont know how true that is mind you but lets see what happens when glow plugs are done.

A forced regen is a noisy process indeed. - Please can you add a link of where to get this software with lead. looking on ebay i am not sure on correct one i need.
 
"Alfaobd" will take you straight there in Google. The author is brilliant - activated my copy when I was at work and took my word for it I would pay. I just use a £5 generic wifi obd dongle.

You need the wired adaptor to access some features, but I haven't had to do that yet.

I use a Windows tablet, but the software is also on the Android store I think.

The regen only lasting a couple of weeks is very familiar. If I regen manually and the engine is warm (i.e. up to working temperature), I always end up doing it again within weeks or days. If I take the car from cold, drive about a mile (the engine has to be up to 70 Celcius) and run a regen it works a treat and doesn't bother me again for at least 6 months.

You can see the difference on the software monitoring. Regen when the engine is hot, and it only takes the dpf to 400 C. If I do it from cold (literally just when the water temp hits 70) it takes the dpf up to 700 or more, which does the job (see Arrhenius equation!).
 
Forgot to add - it always possible you have a faulty sensor triggering the alarms. Easy to access it underneath, but I'm pretty confident mine is OK as the readings tally with what I am generally doing. Might pick up a new one one day if I see it at a good price.
 
Hi,

Many thanks for the information. Very useful.

I will definitely consider getting this app as due to travel to cornwall soon.

The app is £30 but would get me out of trouble should I need it.

Looking at dongles on ebay i have found one labelled

ELM327-OBD2-Car-WiFi-Scanner-DTC-Reset-Bluetooth-Tool-For-iPhone-Android-iOS

Would this be ok?
 
Update

Glow plugs changed now and definitely linked to regen as need heat from them to do its job.

Drove 1 mile down fast road and stopped at a junction and car was very lumpy as was automatically doing a regen.

upon arriving at work i left car idle to complete the regen which lasted 7-10 minutes then engine became smooth again.

Hopefully this has now resolved my issues.
 
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