Vibrations at 1600-1800 RPM

Hello,



"I'm having a problem with my Audi A4 (year 2002). When the engine temperature rises, the car starts to vibrate between 1600-1800 RPM. This gets worse with longer drives."
If I give it more gas or completely release the accelerator pedal at the moment of the vibration, the problem disappears immediately. This issue is getting worse with longer drives.
What I've noticed is that when the car is stationary and warmed up, I can't keep the engine speed at 1600 RPM. As soon as it reaches 1600 RPM while idling, the engine speed automatically increases to 1900 RPM. Is this a normal condition?

Several things have been tried, but unfortunately, none of them achieved the desired results.

It has already been exchanged.
1 PD element + wiring harness.
Flywheel and clutch.
Reciprocating pump.
LMM
Engine mounts.
AGR valve.

The idle speed control seems to be working correctly.

I also checked the VTG linkage using VCDS, and it seemed to be fine, with a difference of approximately 230 mbar.


I have a feeling that the problem might be related to the turbocharger control or the fuel temperature.

Unfortunately, there are no error codes stored in the system's memory.

Does anyone have any ideas? The workshops seem to be just as clueless.
Does anyone have any suggestions on which values I should check when a vibration issue occurs?
I checked the fuel sensor and it measured 1.9 kOhms when warm. Is this a normal reading?

The engine is a 1.9 PD AWX.

Thank you very much.

[Translating...]

Autoscan?

Check the log file once in a while.
Is it correct that the label for MSG indicates "AVF"?