2.0 tdi only regen on idle

[Tomasbjock]

Hello i have recently bought a yeti 2012 110hp 2.0 tdi wich has problem with regen of the dpf. I have scanned it for faulth codes but it has none. 

It was constantly making regen so i got the vag dpf ap and i see the dpf preassure sensor is like constantly åt 24-25 grams of meassured sot... removed the sensor and have tried blowing in the hoses.  Mounted Another preassure sensor and did adaptation and now i Think it shows correct values of meassured sot. It started to regen and dropeddown to 7 grams (20%) then it stoped regen. Drowe it for 20km then it was at 24-25grams again and started to regen exhaust temp got to 600 but when i continue to drive meassured sot did not drop tried running in 4th gear at 100kmh but it still did not drop. Got Home and let it sit in high idle and sure it did drop again down to 7 gram and regen stopped.  Why wont it drop when driving. Only in idle?

[Tomasbjock]

Can it be that there is problem with egr leaking? Thinking it holds a tight seal on idle making regen possible but when i have higher rpm it dont hold?

[Tomasbjock]

Come to Think about it i get 600 degres whilst in high idle regen but when i drive it drop to 500-550 

[Tomasbjock]

done some more testing now, regen starts as it should on 24-25 gram meassured sot, then if i let it sit att idlle the sot level drops, and if i hold low revs like 1500 it still drops, but at 2500 rpm it rises

i have no fault codes what so ever from the car,,,,

 

what should be a normal preassure to se from the dpf preassure sensor, on idle i have like 13-14 on high idle it is around 20 at 2500 rpms it is aroun 100

 

 

[Rustynuts]

On 13/12/2020 at 15:58, Tomasbjock said:

Hello i have recently bought a yeti 2012 110hp 2.0 tdi wich has problem with regen of the dpf. I have scanned it for faulth codes but it has none. 

It was constantly making regen so i got the vag dpf ap and i see the dpf preassure sensor is like constantly åt 24-25 grams of meassured sot... removed the sensor and have tried blowing in the hoses.  Mounted Another preassure sensor and did adaptation and now i Think it shows correct values of meassured sot. It started to regen and dropeddown to 7 grams (20%) then it stoped regen. Drowe it for 20km then it was at 24-25grams again and started to regen exhaust temp got to 600 but when i continue to drive meassured sot did not drop tried running in 4th gear at 100kmh but it still did not drop. Got Home and let it sit in high idle and sure it did drop again down to 7 gram and regen stopped.  Why wont it drop when driving. Only in idle?

Maybe (just a guess) the engine is producing too much soot when under load, so it's not going to burn it off fast enough as it's just producing more all the time.

[J.R.]

A dodgy remap or a tuning box?

[Tomasbjock]

no remap and no tuning, im considering egr and dpf delete and tune for that....

 

 

yes im also thinking it maybe produsec more sot then it should, but cannot find any faulth directly,

 

can ti be the filter just have had its lifetime so it is time to change or clean it?

[Tomasbjock]

but as i sked, what is considered to be normal dpf difference pressure? i have like 12-13 hpa on normal idle and 20 hpa on high idle, 2500rpm stationary is around 80-90hpa, when driving it can get as high as 400hpa when on high revs

[Tomasbjock]

the ash level did read 0,080L and max is 0,175L 

but i was fumbling around with the computer and did reset the ash reading so now it shows 0.000L and onhestly i dont know if someone hade did that before so the 0.080L maybe was not correct, thinking im going to spend my hooliday vaccation with removinga nd cleaning the dpf and fitting a new egr valve assembly

[Tomasbjock]

[PipH]

On some of your shots of the DPF App, the DPF Output Gas Temp is higher than the Input Gas Temp, the DPF must be burning soot to raise the temperature.

 

I suspect you are correct when you say the EGR is sticking open & causing more soot production.

 

You can get one of these :-

https://www.ebay.co.uk/itm/11-EGR-AGR-Emulator-Simulator-Plate-for-VW-Audi-Skoda-Seat-2-0-TDI-CR-II-Euro-5/183869556154?hash=item2acf7ac5ba:g:OaAAAOSw-DRdHK14

which will disable the EGR, but causes engine to emit more NOX.

[Tomasbjock]

That looks like a smart thing to try. Went on trip today 200km. Soot level Rice to 25 then warried between  25-22 while driving.  Came Home and let it idle regen soot droppe to 5 gram and regen stopped drowe 12km and then sot 22gram

[Tomasbjock]

New egr unit fitted today and dpf have been flushed and is soaking in a bubble bath over night.

I sure hope this does the trick

 

[Tomasbjock]

Still problem with soot level rising fast. But it now completes regen while driving in 6th gear in 80 km/h.. only to start again after 10-15km..... what else might cause this? Injector? Air mas meter? 

[J.R.]

I have just fitted one of those EGR emulators, the car feels much more responsive and is currently returning the highest MPG that it ever has but it could be my current touristy driving profile.

 

Tomorros night I will be doing the same curfew breaking 750km journey in the reverse direction at the same speed as I did 10 days ago with the EGR functioning, if I get better MPG it will be quite definitive.

 

Not sure that the EGR did much at motorway speeds though, once I get back into my usual urban driving profile & journeys I will know.

 

It was very easy to fit because the EGR connector came away by pushing the latch in and outwards simultaneously and was visible from above.

[Tomasbjock]

Took a trip to Town today.. soot was 25 grams when i left Home and when i got to Town a trip about 40km it har dropped down to 10 grams...

Then stopped the car and went in store. Bought some injector cleaner and put in the tank with 30 liters of diesel. Drove back Home and soot level rise quick to 25 grams but the started dropping of down to 8 grams while driving and when i left Town the computer Said i would go for 680km and when i got Home it Said 730km so car is taking less fuel and completing regen while driving but still soot level rise fast

[Tomasbjock]

I Think i found the problem. Injector 3 and 4 are returning way less fuel then 1 and 2

[GordoGT]

On 28/12/2020 at 17:48, Tomasbjock said:

I Think i found the problem. Injector 3 and 4 are returning way less fuel then 1 and 2

I'm Interested in this Topic. Especially to see what the fix is...

So did you replace and re-code injectors 3 &4?

 

[Tomasbjock]

I tried replacing them with second hand ones i got four from my workplace that has run only 50000km but all of them returned less then injector 1 and 2... so i tried with 4 other they also returned less. So i changed all 4 of them to 4 comming from a car recently dismantled.  Now all 4 have the same return feed but all of them are returning less then injector 1 and 2 was more like the flow from 3 and 4... but having tried 8 Ones and all get same result i Think this is correct. Soot load was high so i Only had to drive for a short bit to get regen to start. Value dropped even when i was driving 100km... never down that before... but it only dropped to like 12 grams while driving so i stopped and it dropped down to 7 grams and regen stopped. But with a 12 km drive Home it increased from 7 to 16. I started a regen with my diagnostik computer and for the first time ever that seemed to work all other times i tried it only got higher soot load... now it dropped to 6.5 then rised to 7 grams and back down to 6.5 and upp to 7 again so i stopped it. I Think maybe the dpf filter did not get cleaned out enough when i cleaned it. So im thinking of taking it down and trying again...

Edited 29 December, 2020 by Tomasbjock
Added comment

[Tomasbjock]

Oh forgot to mention i coded all injectors and i also tried with Another air flow meter with low milage. 

 

But this is like i Said first time a forced regen i started with a computer seemed to work but not all the way to zero sadly. And the first time car has been lowering soot value while at highway speed 100-110km/h... So it is going in the right direction... hopefully Another cleaning of the dpf might do the trick

[Tomasbjock]

I´m wondering if someone has a readout on a normal working 2.0tdi 110hp on the dpf preassure sensor, as i think my diff preassure is high on like 2000rpm

[J.R.]

That has always sounded like the culprit to me, I always compare the theoretical and measured spot values and also time since last regen, the measured is a always at odds, not sure which triggers the regen.

 

Will try to get measurements for you.

[Tomasbjock]

the meassured soot value triggers the regen not the calculated, but yes if U can take note of the dpf  preassure on low iddle high iddle and on normal drivinga nd on accelerations... mine can rise to 500 on hard acceleration

[langers2k]

A regen can be trigger by either the calculated or measured soot level

 

This is an example on my old car (2.0l CFHC CR140) showing the calculated level hitting 18g and causing a regen:

 

Unfortunately, I never did much logging of the DPF pressure sensor and I no longer have the car. Looks like I did a few random logs looking at different things each drive though:

 

I've attached the original CSV files from VCDS if that helps: logs.zip

 

While I appreciate it's a different engine, it's the same generation so I'd expect the data to be somewhat similar

[Tomasbjock]

Thanx, but are u sure it was triggered by the calculated value and not by the kilometers driven?

 

ok i need if possible readouts with dpf ap of different dpf pressure values on a noral car att 700 rpm 1000rpm 1500 rpm and while driving between 1500-2500 rpm but i realy now thinking the problem with the car really was 2 injectors that clogged upp the dpf.