VW T6 (2018 cxha) - mystery engine jerks and judders av 2-3k rpm problems

[St6]

Not the right airflow can cause wrong fuel mixture

 

[mr.change84]

Perhaps you could make another log with a different logging setup below - as described in post #18

​

Will do the logging today.
I'll tag you when done

 

[mr.change84]

Not the right airflow can cause wrong fuel mixture

Looked down and into the inlet manifold yesterday, and it wasn't too bad.. no gunky at all..
Don't feel it's airflow restricted

 

[mr.change84]

@mmi
requested log.
after looking at live data, we noticed IDE09330 are higher then the others. cyl.1-3 have "same" value, but cyl.4 runs higher number..

we suspect bad injector on cyl.4.. and we will do an return flow test on all 4 injectors..

 

[mr.change84]

@mmi
We found the problem..
Injector 4 is leaking out retur internally.
We just did a return flow test, and nr 4 is overflowing..

 

[mr.change84]

New injector is on it's way and will be swapped on Tuesday.

Will report back if this fixed our problem

 

[mr.change84]

# problem solved #

@mmi and everybody else, thank you so much for all you help..

I love this forum, with all it's information and possible help when needed..

In the end, it was the 4. injector.
Swapped it out and now it's running .

 

[Bert69]

I don't understand this bit. I assume that you weren't allowed to try and start it when you looked at it?

I'm not trying to cast a shadow over your purchase but I do wonder if the belt snapped and bent the engine. Another belt could have been put on and purposely split to try and pass it off as a close call.
It would be beyond immoral but, sadly nothing would surprise me from some dealers.

 

[mr.change84]

@Bert69 ?

 

[Bert69]

@Bert69 ?

@mr.change84 Sorry about that post, it was finger trouble

 

[edge]

I have this issue as well and it is starting to get worse.

Info about van
2016 2.0 150hp cxha
Remapped stage one with Adblue delete.
Still have dpf, and egr is only one year old. with new Intake manifold and o2 sensor recently.

I have been noticing vibration / engine misfire / juddering at around 2000 rpm when engine is under load. Not everytime but sometimes. Most noticable when pedal pressed to the floor.

Recently I feel likt it’s doing it alle the time. And especially when the car regenerates dpf it is actually pretty bad. Whole van shaking. It goes back to normal shaking once the regen is complete.

I also feel the regen takes longer time to complete and fuel consumption feels a bit higher. Maybe a bit lower on power but hard to tell for sure.

I don’t have any codes showing on vcds. I wonder if someone can help me with what to look for and tips for live data I can read out from vcds!

 

[mr.change84]

I have this issue as well and it is starting to get worse.

Info about van
2016 2.0 150hp cxha
Remapped stage one with Adblue delete.
Still have dpf, and egr is only one year old. with new Intake manifold and o2 sensor recently.

I have been noticing vibration / engine misfire / juddering at around 2000 rpm when engine is under load. Not everytime but sometimes. Most noticable when pedal pressed to the floor.

Recently I feel likt it’s doing it alle the time. And especially when the car regenerates dpf it is actually pretty bad. Whole van shaking. It goes back to normal shaking once the regen is complete.

I also feel the regen takes longer time to complete and fuel consumption feels a bit higher. Maybe a bit lower on power but hard to tell for sure.

I don’t have any codes showing on vcds. I wonder if someone can help me with what to look for and tips for live data I can read out from vcds!

Same as we had.
One answer, do an return flow test on the injectors.

Remove topmounted IC and IC bracket.
Disconnect all return fittings on injector.
To check returnflow, we used 4 plastic bottles and some vacuum hose. (Just something we had laying around in the workshop) did the job .
Remember to secure the bottles if you are doing it alone.
When all bottles are connected, start the engine and let it run/idle for 30sec - 1min..
Stop the engine and control the volume of diesel in bottle. If idle in 30sec, you should have almost zero diesel in bottles.
The photo shows our test after 30ish sec. Injector 4 was overflowing to retur. 1-3 was fine.
Changed inj4 and all was goooooood

 

[edge]

Same as we had.
One answer, do an return flow test on the injectors.

Remove topmounted IC and IC bracket.
Disconnect all return fittings on injector.
To check returnflow, we used 4 plastic bottles and some vacuum hose. (Just something we had laying around in the workshop) did the job .
Remember to secure the bottles if you are doing it alone.
When all bottles are connected, start the engine and let it run/idle for 30sec - 1min..
Stop the engine and control the volume of diesel in bottle. If idle in 30sec, you should have almost zero diesel in bottles.
The photo shows our test after 30ish sec. Injector 4 was overflowing to retur. 1-3 was fine.
Changed inj4 and all was goooooood

View attachment 292919

I will try and will update! Thanks!

 

[mr.change84]

I will try and will update! Thanks!

have you tested the injectors?

 

[edge]

have you tested the injectors?

I tried but when I started the engine it was flowing diesel out of the rubber return line so I just abandoned the mission. What a mess it was. But this fault Code has come up lately. Any ideas ?

 

[mr.change84]

I tried but when I started the engine it was flowing diesel out of the rubber return line so I just abandoned the mission. What a mess it was. But this fault Code has come up lately. Any ideas ?

I guess you did't block off the returnline.
we used an small bolt in the splitt where the retur line goes from 4-1.

and the faultcode P13D6 code is often glowplugg on cyl.3. the one that cost $$$

but fist chech harness and stick for dirt or damage

 

[mmi]

But this fault Code has come up lately. Any ideas ?

Surely at idle 830 rpm cylinder pressure 18 bars is not plausible. Should be more than double.



Is the above engine stopped?

 

[edge]

View attachment 316332
Surely at idle 830 rpm cylinder pressure 18 bars is not plausible. Should be more than double.


View attachment 316331
Is the above engine stopped?

No it’s is running at idle. But rpm’s almost 1000 because it’s cold and rpm rise a little to warm up I guess.