I am curious about how my Greenline decides when to regen. You can almost set your watch by the mileage between regens so I am suspecting that it may be mileage triggered rather than monitored for blockage. Doesn't matter how I drive it the regen occurs at the same interval and the duration is also consistently the same.

Are there any techs out there with inside knowledge on the facts about how the DPF regen is monitored and controlled specifically on the 1.4 TDI Fabia

Also a description of the regen process would be welcome. Some cars close the EGR vlave to raise the Nox which helps regen and I wondered if this was the sound I hear when its regenerating.

I know that the DPF also has passive regen. My type of driving has me spend nearly the whole journey in the perfect 'regen zone'. This would mean that perhaps the regens occuring on mine are mostly superflous. I certainly get no change in mpg when it happens. Maybe I have never had a proper regen.

Anyway, all responses welcome. Well, except for all those talking about DPF nightmares and tales of woe....I can find lots of those if I look, I am really after the more technical side.

Edited 7 November, 201015 yr by raisbeck

I know my signum used to do it based on driving style, so it assumed certain things rather than detecting the back pressure from the DPF etc.

Andy

http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

One of many DPF articles on the web, also considerable number in the forum.

Not all problems are the DPF a lot of members have had sensor failures, best get car checked out by a reputable dealer.

http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

One of many DPF articles on the web, also considerable number in the forum.

Not all problems are the DPF a lot of members have had sensor failures, best get car checked out by a reputable dealer.

A very informative link. Pretty sure mine doesnt use any adblue type system. The DPF and the catalyser are combined near as I can tell. The nox is taken care of by the EGR system.

My car doesnt have a problem at all. Its working fine. I just wanted to know what the process was for triggering a regen.

Its a monitored system, the flow through the DPF is monitored, and when it reduces a regen is triggered.

Saying that , my dads greenline in 10k miles of mostly town driving has not triggered any regen at all. If you car is regularly regenerating then there maybe a sensor problem.

Its a monitored system, the flow through the DPF is monitored, and when it reduces a regen is triggered.

Saying that , my dads greenline in 10k miles of mostly town driving has not triggered any regen at all. If you car is regularly regenerating then there maybe a sensor problem.

Thanks for that Mannyo. It is possible that what I perceive to be a regen is nothing of the sort. Certainly its not like those with a 1.6 CR describe. Its not hot or even smell hot. Instantaneous MPG is unchanged. It just sounds a little more noisy (more audible sort of exhaust sound) and is somehow 'different' in the way it drives and accelarates. It does this around 120 mile intervals. Car spends its life on fast A road and dual carriageway mostly.

Always been like this since new and I dont see it being a problem. Many people probably wouldnt even realise its doing it. Doing same journey every day of 116 miles you get to know every little nuance of the car.

Always had Esso fuel, not that that really makes a difference.

Anyone else with a PD Greenline ever noticed this periodic change in how the car sounds and drives (lasts about 5-10 mins) ?

I had just assumed it to be a regen

Thanks for that Mannyo. It is possible that what I perceive to be a regen is nothing of the sort. Certainly its not like those with a 1.6 CR describe. Its not hot or even smell hot. Instantaneous MPG is unchanged. It just sounds a little more noisy (more audible sort of exhaust sound) and is somehow 'different' in the way it drives and accelarates. It does this around 120 mile intervals. Car spends its life on fast A road and dual carriageway mostly.

Always been like this since new and I dont see it being a problem. Many people probably wouldnt even realise its doing it. Doing same journey every day of 116 miles you get to know every little nuance of the car.

Always had Esso fuel, not that that really makes a difference.

Anyone else with a PD Greenline ever noticed this periodic change in how the car sounds and drives (lasts about 5-10 mins) ?

I had just assumed it to be a regen

My Greenline is just coming up to 20,000 miles. In the year I have been driving it I've covered 12000 miles and I've only had the DPF warning light 3 times, and that has cleared within about 15 minutes when driving as per handbook routine. I haven't had a warning now since about August, but the car did have a good clean out the Autobahn in September. I do hear a change in the exhaust note from time to time, especially when doing shorter trips which I assume is the engine adjusting the timing and fuelling to heat up the DPF.

My Greenline is just coming up to 20,000 miles. In the year I have been driving it I've covered 12000 miles and I've only had the DPF warning light 3 times, and that has cleared within about 15 minutes when driving as per handbook routine. I haven't had a warning now since about August, but the car did have a good clean out the Autobahn in September. I do hear a change in the exhaust note from time to time, especially when doing shorter trips which I assume is the engine adjusting the timing and fuelling to heat up the DPF.

That sounds about right. Maybe the Greenline does a milder sort of regen more often rather than the full on gas mark 9 they do on the new CR engine. Havent had the light myself for over 12000 miles but the car is only ever used on fast A roads, motorways etc. Might just be luck or possibly the fuel .....

I cant recall if it was you or another Greenline driver who posted about the difference in the car after its run in. I was sceptical at first but after 12000 miles its a different car to drive. The longer gearbox is brilliant given that the engine is now smoother and more responsive for any rpm. I am glad I went for the Greenline instead of the standard TDI. Was a bit uncertain at first.

I wondered if mine was "re-genning" as I clogged up the M20 this evening as I drove to work. Felt a little "flat" with the power.

I wondered if mine was "re-genning" as I clogged up the M20 this evening as I drove to work. Felt a little "flat" with the power.

Other folks with the CR engine say it idles higher when its regenerating the DPF. The PD doesnt idle higher during regen, well mine doesnt anyway. I would be surprised if yours was affected much in the way it drives as the CR can inject as much fuel as it likes at any time. The PD is limited in how much it can inject and when due to the injection being dictated by the cams. It does have a modified injector camshaft to allow regen but the CR should be better able to control the regen process.

Does the sound from the engine alter during the regen on a CR Fabia as it does on the PD engines ? If your not listening out for anything slightly unusual its easy to miss.

As I have said previously, the only time Ive considered that the car was regenerating was that there was a slight burning smell coming through the vents on the dash. it only lasted a few minutes.

The last time the car did was just over a week ago and since then have done about 200 miles. Doesnt concern me as the car is still running in.

Incidentally, the car on its last tank of fuel has been doing about 5 miles to the gallon more than the previous tank, so is slowly improving. I doubt i`ll ever get to 68 mpg overall though!

Regards

Grahame

Edited 8 November, 201015 yr by threadbear