Motor problems with the ARL engine (1.9L with 150hp)

Hello,
I own a Golf 3 TDI, which I converted about 2 years ago using the "Big" PD TDI engine, engine code ARL. It has run very well so far, but now it's having problems. Mileage approximately 60TSD.

When accelerating, it produces a very strong exhaust, and there is less power available. The power loss is not extreme, but it is noticeable. Furthermore, the exhaust increases with increasing engine speed, and the engine becomes sluggish. This is accompanied by a distinct hissing/whistling sound coming from the engine compartment. Fuel consumption is hardly increased.
I have already replaced the air filter, but that didn't help, nor did cleaning the LMM (which was replaced about 10,000 km ago). There are no new errors in the control unit (no new errors because my ABS speed sensor on the right rear is defective...). I checked the AGR valve on the "cold" side, and there were only very few deposits that I removed, and the valve also moved freely. I checked the vacuum hose "visually", but it also seemed to be in order at first glance, as did the intake pipes (as far as you can see). I also took a test drive and logged the data using VAGCOMM (measuring blocks 03, 08, 11), which you will find in the attachment. I am having some difficulty interpreting these values, but I believe the boost pressure of 2.5 bar during the two full-throttle phases between 2000-4100 RPM is acceptable. I hope the turbo is not the culprit (it's very expensive...).
I would like to remove the LLK pipes and pressure hoses and carefully inspect (and verschandeln if necessary) this weekend, and also to disable the AGR valve. How can I inspect the large LLK, which is located in front of the water cooler? Do you have any other suggestions?

Greetings from the North
Olli [/list]

How can I attach the file (the log) here if it's not possible, I'd be happy to send it via email.

Hmmmmm.....

'Rumbling' usually indicates a lack of boost. Your described hissing is also another indication. However, a single test run is usually not conclusive. Even if your boost pressure reaches 2.5 bar at some point, that is still not necessarily an indication of a functioning compressor or a healthy intake system. Search for the 'hole' and check the runout of the VTG.

Additionally, the technical article on performance loss also provides further assistance.

[Translating...]

danke, werde ich natürlich machen, wie kann ich die Leichtgängigkeit des VTG prüfen? könntest du evtl. etwas aus dem Log von VAG erkennen, könnt ich dir Mailen

To verify the VTG, you can find a lot of information here, either in the technical articles or using the search function. Why send logs? If you take Measurement Block 11 and take values 2 (Target) and 3 (Actual) and create a diagram using, for example, Excel, you will see what is happening.

Hello Olli,

Firstly, it's certainly not a 2.5 bar charge pressure, but rather a maximum of approximately 1.5! Furthermore, the hissing sound, as already mentioned by Lapke, is a clear indication of a leaking air intake.
How to test the VTG for ease of use has already been discussed countless times and should be a matter of course after studying the relevant articles. Please don't take me the wrong way, but these threads have already been discussed here far too often. If you have any questions, I'm happy to clarify them.

Let's go: /viewtopic.php?t=3004

Have a good time.

No, I don't want to bother anyone with questions that have already been asked. I will also be conducting further tests over the weekend. I was just hoping that someone here might be able to take a look at the logs, as I am new to this and would like to learn with the help of an experienced user. I am also not too lazy to implement the given hints in the car. I thought that perhaps more could be gleaned from the logs. I am doing a conversion, and the engine and the noise of the turbocharger are much louder and more intense in the Golf 3 than in the relatively well-insulated Golf 4, and it seems to me that the whistling has become louder. Of course, I can also imagine this if you listen carefully and if you have a problem, you can find a lot of it in Frage (was ist das, war das schon immer so oder ist es jetzt erst so...). The inspection of the intake system and the turbocharger likely requires (at least regarding the turbocharger) the removal of the engine, as the engine bay of the Golf 3 is somewhat smaller than that of the successor. If there are any hints in the log, I will of course try that first. I've looked at some articles here in the forum and compared your recommended values, but I'm having some trouble with them because I can't find them for the ARL motor either.

Hello,

then please extract the log file, I will then upload it here. But please do not as a wild column of numbers.

so hab ich es dir per PM geschickt

Hier das Log, zunächst ohne weitere Bewertung:
[2024-07-24 10:00:00] INFO: Starting process.
[2024-07-24 10:00:01] INFO: Reading configuration file: config.ini
[2024-07-24 10:00:02] INFO: Database connection established.
[2024-07-24 10:00:03] INFO: Starting data import.
[2024-07-24 10:00:05] INFO: Imported 100 records.
[2024-07-24 10:00:06] INFO: Data import complete.
[2024-07-24 10:00:07] INFO: Starting report generation.
[2024-07-24 10:00:09] INFO: Report generated successfully.
[2024-07-24 10:

My God, this number chaos.

Please examine values 2 and 3 of Group 11! You will never reach the target value, even at speeds above 2000 u/min. Furthermore, you have extreme fluctuations when 'tapping' (referring to a specific operation). Therefore, please check the VTG (Variable Torque Control) and the tightness of the air intake connectors, including the air intake cooler! The air mass value is, in my opinion, OK.

Edit: VTG should not be the one responsible. ...this is a direct counter.

Hello Zak1976,
If you hear hissing from under the hood, there's likely a leak somewhere after the ATL. That should also be detectable at the stationary vehicle when accelerating.
Best regards,
Günther

First of all, thank you for the response. After further consideration, I also suspected a leak between the turbocharger and the AGR valve, or a defective turbocharger boost control unit, but this didn't match the measured values.
Do you have a tip on how I can specifically check the large LLK (excluding visual inspection)?

A leaking intake manifold is typically identified by an oil mist at the leak location.
It is also possible to remove the intake duct from after the compressor of the turbocharger up to before the AGR valve. Simply insert a sealing plug into the ducting after the turbocharger. Also, before the AGR valve, from the direction of the intercooler. But in these plugs, you can install a tire filling valve and then apply 2 bar of pressure using a compressor. If this pressure is gone after, say, half an hour, then your intake duct is leaking. (Caution!) **Important: Pay attention to pressure equalization!** ) If not, it is probably due to a non-sealing AGR valve.

But here, the search function would also have been helpful.

Wie lassen sich (z.B. bei einem Leck) diese starken "Abfall" erklären, wenn die Beschleunigung "wegfällt"? Das sind ja teilweise Abweichungen von fast 100%??????????

Hello,
can be derived from the rule-time constants of the VTG control.
Best regards,
Günther

Due to the more aggressive control of the VTG to achieve the target LD, the turbine blades are quite steeply positioned in the exhaust stream. This means that it takes a certain amount of time to position the blades in the exhaust stream so that the target LD is achieved during the 'adjustment' process. Also, this sluggish behavior depends on the exhaust stream. However, these overshoots are present in such systems. If your intake air path is now okay, you will likely still experience similar overshoots. Not as severe, probably. Also, you will certainly experience overshoots when regulating the maximum. Monitoring the loading pressure.