Car always in REGEN

nhraracer90

Well-known member
Joined
Dec 30, 2012
Location
WV
TDI
2010 Jetta Sedan
Hello! I recently had my DPF replaced under the extended warranty (thanks VW) but now my car seems like it is always in REGEN. I have a 1hr- 1h30min drive each way to work and both ways the car goes into a REGEN. It used to do a REGEN roughly once a tank full (this was before the new DPF and *fix*). The dealership has looked at it and said no fault codes and they do not see any problems. They also said after the *fix*, they will go into REGEN more often. Has anyone else been experiencing this?
 

AirmanTDI

Veteran Member
Joined
Mar 20, 2011
Location
Great White North eh
TDI
2011 Jetta TDI Grey/Black
I had an hour drive one way to work and my ‘11 would regen on the way in and the way home. Should be fine.


Sent from my iPhone using Tapatalk
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
Sounds like pretty normal behavior for an updated non-DEF equipped TDI post fix...
The LNT"trap" is so limited in capacity, it must Regen regularly....that's why HD truck maker, and VW when forced to, moved on to DEF using technology to meet emissions rules.
To put it in the perspective, a HEAVY DUTY truck with a HUGE LNT trap regins every 7-10 minutes. Yes, it dies consume extra fuel...and thats why most if the industry moved away from the LNT traps the the technology that uses DEF.
 

Wilkins

Veteran Member
Joined
Aug 19, 2005
Location
British Columbia
TDI
05 Jetta Wagon 5sp, 10 Sportwagen 6MT
If I am not mistaken there are three different regens. Two involve the LNT trap and the third the DPF. NOx regens occur very frequently on a fixed car compared to pre fix, less than five minutes apart I think but only last maybe 15 seconds. The second LNT regen is much less frequent and longer, I think I am getting one every 50 km for maybe a minute. In my car both of these are very smooth (so far) and I only know they are happening because my Polar tells me.

DPF regens seem about the same as pre fix for me, although I tend to think the soot level doesn’t increase as fast as it did. Really too short trip and weather dependent to tell any difference.
 

vincej

Veteran Member
Joined
Jun 26, 2015
Location
Calgary
TDI
2014 Golf Wagon
From someone who knows almost nothing about these cars, is always in regen better or worse than never in regen? After putting a couple hundred kilometers on a new to me 2014 car I haven't heard it come on yet.

From my previous 2013 car if it was on all the time that would be annoying. It would run on for some time even after the key was removed from the ignition.
 

murphyslaw

Veteran Member
Joined
Mar 31, 2014
Location
Alaska
TDI
'14 TDI JSW/Sunroof/Nav/Man
Since the software update 2 years ago my car is in and out of regen every day. I do ~100 miles round trip daily. Used to only do it every few days maybe twice a tank of fuel.

Can't wait to get the "fix" done and for VW to send me the check so I can have Malone "unfix" the whole thing.
 

Matt927

Veteran Member
Joined
Dec 29, 2013
Location
Northeast
TDI
several
Purchase a scan gauge so you can monitor various EGT sensors. I see much more frequent LNT trap regens (brief excursions to 1000+ degree temps on post turbo sensors). Probably double the amount of DPF regens I saw before (extended 1200-1400 on the turbo and 1000+ on the DPF sensor). Regardless I do not shut the car down till I see the less then 400-450 on pre turbo and DPF sensors.

When you shut the vehicle down and the electric fans are running, you are cooking your turbo. An idle temperature stabilization will benefit all your exhaust comments, especially the turbo.
 
Last edited:

vincej

Veteran Member
Joined
Jun 26, 2015
Location
Calgary
TDI
2014 Golf Wagon
So far I have put 1000kms (600mi) on my new purchase and never heard the regen fans come on. What are the consequences of that? Did someone do something to the car? I haven't tried my scanner on it yet and doubt if it will give much for readings so maybe I'll look into the Ross tech. My wife doesn't like travelling in this one so it will just be my work car.
 

AirmanTDI

Veteran Member
Joined
Mar 20, 2011
Location
Great White North eh
TDI
2011 Jetta TDI Grey/Black
When I had my ‘11 I had the ScanGuage II and had EGT set so I could see when it was going through a regen


Sent from my iPhone using Tapatalk
 

Wilkins

Veteran Member
Joined
Aug 19, 2005
Location
British Columbia
TDI
05 Jetta Wagon 5sp, 10 Sportwagen 6MT
Vince I once went a whole winter without ever having the fans come on and they haven’t come on yet since I have had the fix done. I have only had them come on if I am stopped or shut the car off during a regen so I don’t think it’s anything to worry about

I can monitor engine behaviour very easily with my Polar. Since the fix, two DPF regens so far, the first a short one immediately after the fix was installed and the second 400 km of in town driving later. I used to go less than 300 km between regens around town with an indicated soot load of 16.5 g, this one went to 23.5g and the regen request counter was at 7 whereas before it only went to 5. Post regen the soot load was at 5.5 instead of 3.5 and the regen itself took about 10 km at 80 - 100 km/ hr. I also had the impression that peak temperatures were lower. I think I used to see 1200 F (650C) in and out of the DPF for about 15 seconds at the end of the regen and this time it barely went over 1100 F (600 C).
 

vincej

Veteran Member
Joined
Jun 26, 2015
Location
Calgary
TDI
2014 Golf Wagon
I noticed while having the hood up to do a DSG oil change that there is a sticker under the hood stating that the fix has been done. There is also something behind the catalytic converter that I don't remember seeing on my previous car. I won't worry about it any more. As for the oil change probably I did not need to do it as the oil came out pretty clean, meaning it was done previously.
 
Top