A6 C5 2,5 V6 TDI No power output from 3.000 rpm

Hello!

I've been trying the search function for quite some time now, and I haven't really found anything helpful...

Yesterday, I inspected a 1999 A6 2.5 TDI quattro tiptronic with 240,000 km. The car has been well-maintained and has all its service records.

The Problem: It runs okay when idling, but struggles significantly from 3000 RPM onwards and has very little power.

When revving up, it runs better, but something is still wrong: It seems that when idling, between 3500 and 4000 RPM, it occasionally stalls, then revs up to the rev limiter. When exceeding this "wall" while idling, you can hear a PFFFT sound coming from the front, as if the VTG adjustment is doing something.

In the memory, the following error was stored: "Suction tube pressure, control limit exceeded". After deleting the error, there was no improvement, but after a 2km test drive, the error did not reappear.

I also performed the actuator diagnosis. According to my assessment, the VTG adjustment function is working quite well.

Furthermore, a friend of mine has performed a log drive with vagcom and recorded channels 10 and 11. I can gladly post the log tomorrow. As it appeared, the "should" and "actual" boost pressures were usually quite similar, with the maximum boost pressure being around 2.1 bar, if I recall correctly.

Perhaps someone here has an idea. I need to decide by Monday whether to take the Audi...

Best regards and thanks from Vienna,
Ingo

I've been trying the search function for a while now, and while I've found some threads, it hasn't really helped me...
Hi,
Try using the search function again, using the MKBs AFB, AKN.

Best regards, Kurt from HH

[Translating...]

Stchwort f. Suche: Nockenwellen

[Translating...]

vwSchrauber wrote:

Stchwort f. Suche: Nockenwellen

Das glaube ich eher nicht. Viel mehr kann es am Turbolader liegen, oder verstopfter Auspuff oder so. Selbst mit 4 kaputten Nockenwellen laufen die Teile noch richtig gut.