BKD 2.0 TDI: Log Evaluation & Diagnostics

Hello everyone,
I have the following error code on my Golf 5 BKD 2.0 TDI with 140 hp and 65,370 km:

Code:

Adresse 01: Motor        Labeldatei: RKS\03G-906-016-BKD.lbl    Teilenummer SW: 03G 906 016 AQ    HW: 028 101 184 8    Bauteil: R4 2,0L EDC G000SG  7000     Revision: 12345678    Seriennummer: VWZ7Z0E2487915    Codierung: 0000172    Betriebsnr.: WSC 01279 785 00200    VCID: 72E053081429 1 Fehler gefunden: 16618 - Ladedruckregelung: Regelgrenze überschritten             P0234 - 000 -  -              Umgebungsbedingungen:                     Drehzahl: 2226 /min                     Drehmoment: 216.0 Nm                     Geschwindigkeit: 74.0 km/h                     Last: 46.3 %                     Spannung: 14.44 V                     Binärwert: 00101000                     Druck: 1876.8 mbar                     Druck: 2254.2 mbar Readiness: 0 0 0 0 0

I just checked the VTG (variable geometry turbine). It moves freely with a syringe and doesn't seem to be stuck. I also inspected the vacuum hoses and didn't find anything wrong.
When I run the actuator test using VAG-Com, the VTG moves just like it does when using a syringe. I've done this in both cold and hot engine conditions.
I also took some logs from MWB 03, 08, and 11, which show some overboosts. The boost pressure is always about 200 mbar above the target value.

Now my question is, is this normal for this engine?
If not, is the turbo blown, or what's your advice?

"Thank you very much!"

Sure, here is the translation of the text from German to English:

"PS:"
Link to the log files: https://community.dieselschrauber.org/en/viewtopic.php?p=182736#182736

Hi,

It looks like the VTG (ventricular toothing groove) isn't opening wide enough.
The N75 releases pressure quite a bit (low percentage), but it still lets out too much.

Can you extend the rod further outwards than its own length?

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.
Is the box damaged?

- Revision 12345678
- The maximum torque of 362 Nm seems a bit high (my BMR releases 370 Nm).

Hi,

I've just checked the VTG (Variable Turbine Geometry) again. I can't move the guide vanes any further; they are already at their maximum position. You can also hear the mechanical stop engaging on the VTG/vacuum sensor.

No, the car's ECU (engine control unit) is not chipped. The car was purchased new and nothing has ever been modified (no chip or tuning box).
Otherwise, everything else is original.

Sure. Please provide the text you would like me to translate from German to English. I will only provide the translation, without any explanations.

Hello,

You can try unscrewing the vacuum cylinder from the loader; then you'll see if the VTG (Variable Transmission Geometry) really moves freely. The adjustment lever must drop down completely on its own; even the weight of the cylinder is many times greater than the force needed to actuate it.

The distance along the path near the adjustment lever with the attached container is approximately 1 cm.

dieselmartin wrote:

(my BMR indicates 370)

Expected: Maximum torque of approximately 390 Nm, limited by the transmission's torque capacity.

Sure, here is the translation of the text from German to English:

"LG" can be translated as "Best regards" or "Sincerely". It is a common abbreviation for "Liebe Grüße", which means "Warm greetings" in English.

Hello,

Today I tried to see if I could unscrew the vacuum diaphragm. Unfortunately, I couldn't. One of the screws on the vacuum diaphragm is located behind the adjustment lever, and it's impossible to remove when the part is installed.
The travel distance of the adjustment lever is approximately 1 cm. This corresponds to a volume of about 50 ml when I draw it up with the syringe.
The same behavior occurs with the VTG when I control it using VAG-Com.

Does anyone have any other suggestions for how I can narrow down or identify the error?
If it's the turbocharger, has anyone ever removed one of these before?
What exactly needs to be removed? Is the turbocharger removed from below or from above?

I am grateful for any advice.

Sure. Please provide the text you would like me to translate from German to English. I will only provide the translation, without any explanations.

I've already experienced "sticky" vacuum cups, meaning that when the vacuum hose is disconnected, they only slowly return to their original position. This could also be a potential area for improvement.

I think that if you're not getting the desired results and you've already checked the usual things, then there's no way around upgrading the charger.

Best regards, Rainer.

Hello everyone,

Here's the solution to the problem, late but eventually found.

I had the following error:
"16618 - Charge pressure control: Limit exceeded."

Well, this error is a consequence of another error.
As is well known, these engines sometimes have a defect in the cylinder head. This was also the case here. The burning of coolant caused the variable geometry turbo (VTG) to seize, although not always. Consequently, this resulted in the error.
Result: new cylinder head, new turbocharger.

Sure thing! Please provide the German text you would like me to translate into English. I will only provide the translation without any explanations.

P.S.: To be sure whether you have a cylinder head from the problem series, there is a three-digit number on the head itself. This number is located at the back, on the driver's side, near the AGR cooler. If this number is less than 125, then it is one from the problem series.

Thank you for the feedback!