How To Tell If Your DPF Is In Regen Mode? - Alfa Romeo Forum
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Hmmm How To Tell If Your DPF Is In Regen Mode?

How can I tell if my 1.9 16v JTDM is doing an auto regen????
The reason I'm asking, is because I've noticed on a few ocassions over the last few months;
1. Seriously poor MPG for about 15 mins or so.
2. A puff of grey smoke from the exhaust, which I've seen through the back window in the rear view mirror. This only happens if I've just hoofed it and let off the accelerator.
3. The turbo guage acts differently. ie, when I lift off the accelerator it drops suddenly to zero, unlike normal operation, where it slowly decreases and settles above zero.

All these symptoms happen at the same time and last for 10 to 15 mins....well, except the smoke, which usually happens once for maybe a second or two.

Is this normal? Do I have a failure in the making? What exactly are the symptoms of a regen?
If you know.......If you can help.....then maybe you should hire errrm...sorry....wrong forum .

Cheers, Chris.

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Sounds like a classic regen to me. My 1.9 jtdm does the very same - always a bit of a concern when cruising on the motorway and the instantaneous mpg is in the high teens! Fortunately, it always recovers.
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Sounds like a mirror image of the times it did it in my 159 1.9jtdm.
Once it is over then all is well again, just try to make sure it gets through the cycle, there are issues with the limp mode etc.. if it doesn't get through the cycle. Usually fine, but the problems I had with my CEL and such were when a regen was stopped mid way.

Give it a good boot every now and again and all will be well, thats what I told the wife as we screeched off.....
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I agree with Wynne - all perfectly normal but let it run through its cycle as problems can occur if you interrupt the flow.
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yes classic symptoms... if my mpg is reading low i'll let off the gas and if the turbo gauge drops to zero then I know its doing a regen. Then its time to keep the revs high and give it a few bootfuls of right foot to ensure shes nice and clean again
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1) and 3) definitely, but I have NEVER had sign of smoke or haze.

A deeper boom from the exhaust is another sign, I usually hear that and lift off to watch the turbo boost guage to confirm than make sure the engine has some load till its done.
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Any conscensus on how often the regens happen?
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The specialist I use for the Alfa told me it depends upon how the car is driven and used. If you don't get the engine up to temp with lots of shorter journeys, it will clog up quicker.
If you do a lot of motorway and use a bit of right foot every now and again, they clog up with less ease.
Seemed to work with me. 22 miles across Brum and back each day followed by a weekend blast up and down the M5 saw off all but one DPF problem.
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About 3 weeks ago went over to Huddersfield and it started to regen on the hill up to Ainley Top. Since then done around 1000 mixed miles, and it did the same again today, smoke and consumption way down in the teens. Weird it should happen in the same place? Seems to have completed its cycle now...
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