Fluctuating idle after cold start - 2.5 TDI V6 AKN

Hello,

After finding numerous posts using the search function regarding fluctuating idle RPM, but still unable to identify the cause of my problem, I decided to create a new topic.

A4 12/1999 2.5 TDI AKN 77 TKM

He starts up perfectly and all the properties that can be subjectively determined are as they should be. However, it is observed that after the COLD START, the increased idle RPM cannot be maintained, and there are fluctuations of around 1000 RPM. This takes about 30 seconds, and once the RPM is reduced to 900 RPM, the RPM fluctuations become smaller and disappear. If I manually increase the throttle, it never fluctuates. Is it so cold outside that it initially runs around 1100 RPM, and there are surprisingly no RPM fluctuations - only when the RPM drops into the 1000s?

If the outside temperature is above 8 degrees, it will only run up to approximately 900 RPM and nothing unusual can be detected. As mentioned, otherwise everything is really okay, and no timing belt replacement was performed.

Has anyone ever experienced this phenomenon? Or does anyone (exam-) know a solution for it? Can I rule something out myself (initially without VAG)?

I would like to thank you in advance.


Best regards,
Joerg B.

[Translating...]Könnten Anzeichen für bevorstehende Pumpenprobleme VP44 sein,bei meinem hat es so angefangen ( siehe Thread ) und mein Kolleg mit dem AFB V6 von 1998 ging es auch gleich.
Meine Pumpe war nach 167.000 gefressen und dadurch hinüber.
Besser mal die Pumpe checken und den Tank nicht immer leerfahren,Wasser und Schmutz bedeutet für diese Pumpen den TOD.

[Translating...]

@Beeralpina:

Gibt es was Neues?
ch habe das gleiche Problem, Laufleistung 142000km, Tank noch nie leergefahren und noch nie ohne Diesel georgelt, ausser vielleicht die Werkstatt

My Afn (4-cylinder engine) makes these kinds of noises when one or more of the light bulbs are faulty.