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

[mr.change84]

5 minutes normal driving would be a good reference. A couple (2-5) of hard pulls to demonstrate the issue would be ideal. All of them can be in a single log. Some bookkeeping would be helpful - to time stamp when the issue surfaced - see the "Marker" above.

Will do logging today after work.

Pre. logging we will clean the manifold MAP sensor, change fuelfilter and manually regeneration of DPF.

 

[DaveD]

After you replaced the cam belt you say, "And after 200m at 3k, engine came really alive.. all was good. Pulled really strong and sound so sweet."
To me that strongly suggests you have correct timing and no bent con rods or other mechanical engine damage.

 

[mr.change84]

After you replaced the cam belt you say, "And after 200m at 3k, engine came really alive.. all was good. Pulled really strong and sound so sweet."
To me that strongly suggests you have correct timing and no bent con rods or other mechanical engine damage.

It was air inside injectors that cause it to run on 3 cylinders. And when giving 3k rpm, they really opened up and self breeding themselves

 

[mr.change84]

@mmi
engine blockmap data

 

[mr.change84]

@mmi
only thing done before the blockmap and log, was cleaning the manifoil MAP sensor with maf cleaner

log from run.
multiple marker point when car/engine war jerky/juddery

 

[mr.change84]

@mmi
Last log of the day. 2min idle, hard pull 4. gear, 2min idle.

Thank you so much for all your help, really appreciate it.

 

[mr.change84]

Status after today's work on the van.

We have done this and it has not affected the problem. Still jerks and judders around 2000-3000rpm on light throttle movment/use.

- cleaned the MAP sensor at manifoil.
- changed diesel/ fuel filter (with vcds)
- Done a stand still DPF regeneration via vcds.

 

[mmi]

Thanks for the logs. Had a brief look into the data just to eliminate the most obvious - I believe engine speed sensors (crankshaft and camshaft) are just fine. Need to have a deeper look tomorrow.

Still jerks and judders around 2000-3000rpm on light throttle movment/use.

What about when using cruise control in that rev range - e.g. gentle uphill - causing light throttle increase?
Any noticeable dual-mass flywheel issues?