Touareg: Intermittent Jerking - 4.2 TDI Fix

Hello everyone,

I've been experiencing intermittent problems with my Touareg 7P 4.2 TDI for weeks.
The car occasionally jerks after gear changes within the RPM range of 1500 to 2000 RPM. It's a single jolt occurring approximately 1 second after the gear change, but it happens sporadically.
It is usually more pronounced when the engine is cold.
When accelerating quickly, you don't notice any jolts.
It feels like there's a brief interruption right after the gear change.
A transmission flush has already been performed, the mass airflow sensor (MAF) has been replaced, the EGR valves have been replaced, the fuel pre-pump has been replaced, and the intake manifold has been cleaned.
Best regards, Raimund.
There are no error codes in the engine control unit (ECU) or transmission control unit (TCU).
Does anyone have a suggestion for something I could check or some help they can offer?
I did some logging runs related to throttle position and fuel injection deviations.
Perhaps someone would like to review the LOG trips.
I placed a marker after the jump in the first file.

Best regards, Raimund.

Hello,

How did the intermittent jerking/stuttering occur?
Is this something that happens automatically, or only after a modification or service to the vehicle?

Best regards, Rainer.

Hello Reiner,

A few weeks ago, I replaced the AGR valves.
"There was an error: insufficient flow."
VW has installed the diesel update.
The occasional jerking had been present sporadically before.
However, it has become more frequent over the past two weeks.


Best regards, Raimund.

Hello.

Can someone help me with something?
Who has experience with this engine?
Could the swirl flaps be causing the problem?

Best regards, Raimund.

Hi,

I'm not familiar with this engine, but if the swirl flaps are controlled pneumatically, I could imagine occasional malfunctions.

The only solution is to obtain a Service Security Password (SSP) for the engine, open the hood, and inspect it. If there are pneumatic valve actuators, check for leaks in the diaphragms of the actuators and in the hoses connected to them. Of course, the solenoid valve that controls these actuators could also be internally blocked.

Best regards, Rainer.

Hello,

The swirl flaps are electrically controlled.
I once checked the rail pressure calibration points and quantity deviations.
Quantity deviations in the cold operating state after engine start and when the engine is warm.
Could someone please review and evaluate these values?

Best regards, Raimund.

Hello,

The fuel injection volume deviations are very good.

At the calibration points and with a quick comparison to...
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
I can't see anything unusual either.

Best regards, Rainer.

Hello Rainer,

Thank you for your feedback.

Best regards,
Raimund