Ibiza 6L: Low Power Below 2500 RPM?

Hello there,

I've been reading and searching here for a few weeks now, but I haven't really made much progress.
Maybe you have a brilliant idea.

Here's my problem:

"For about 6 weeks now, my Ibiza (manufactured in March 2004, 70,000 km, automatic transmission) has suddenly lost power, with the engine barely reaching 2500 rpm (this happened within approximately 200 km of highway driving). Initially, I attributed it to cheap gasoline from the Czech Republic, as I had just filled up there (although at a reputable gas station)."

After I had refueled with approximately 2 x 30 liters of fresh diesel, I thought I could feel some improvement, although I was probably just getting used to the poor performance, as the logs from the VAG-COM prove.

Okay, I'm ready. Please provide the German text you want me to translate into English.

It is clearly visible here that the actual load deflection (Ist-LD) only reaches the target value starting at approximately 2400 rpm.
I still reach my top speed, although I have the impression that it's a bit slower than before.

What's frustrating about the whole situation is that the 4-year warranty just expired, and my local Seat workshop is 30 km away, which means I need a rental car for every visit.
Therefore, I would like to narrow down the problem as much as possible beforehand and, if possible, fix it myself, assuming that it is something within my capabilities as someone who works on streetlights and garage doors.

Thank you in advance for your efforts.

Hi,

Good problem description and decent diagramming: an exemplary introduction to the forum .

The graph suggests that the VTG (Variable Turbine Geometry) has an "offset towards open," possibly due to insufficient control pressure. That's where I would start looking for the problem.

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

"Hi,"

Simply run measurement block 11 in the basic settings mode and see if the VTG adjustment lever quickly reaches both end positions and doesn't get stuck.

Best regards, Rainer.

Thank you very much for your answers.

"VTG sounds logical – I probably could have figured that out myself, but sometimes you get so caught up in the details (like LMM, EGR, etc.) that you lose sight of the bigger picture."
Well, it's also my first TDI engine that I have to practically work on myself, and it's not an old motorcycle engine.

Then I will take a closer look at the VTG this weekend - it should definitely be doable for me, thanks to your excellent articles.

Yippie!!! My car is running like the devil out of hell again.

Cause:
Probably one of those little critters with razor-sharp teeth.
A nearly imperceptible 2mm "cut" was present on one of the vacuum hoses, located in a perfectly concealed spot. It was wrapped twice with electrical tape, and now the turbo whistle is audible again from 1500 rpm.

One thing is still worrying me, though:

I noticed a small amount (2-3 drops) of oil leaking from a connection point on the pipe between the LLK (likely referring to a cooler or valve) and the AGR (Abgasrückführung - exhaust gas recirculation system). I removed the pipe, and there's a slight oily film visible inside.

Ideally, the fresh air should not contain any oil.
Is this behavior normal, or does the turbocharger already have bearing damage?

"Edit: I found posts suggesting that some oil is normal (from the turbo and engine ventilation system), but the leaking hose should not be."

Can I use a 10W40 oil (provided it meets the appropriate VW PD-turbo specification) in the ASZ engine without any concerns, to prevent oil from leaking through the seals in the turbocharger?

Okay: without a lift or pit, it's practically impossible to even get a visual contact with the VTG valve – my colleague and I spent over half an hour searching for this thing, and we only found it when I crawled under the car .

Edit: I also found a post by ulf stating that it can only be examined from the top by "feeling" around (checking for ease of movement, travel distance, etc.).

I've made a few edits above and added answers to my questions.

The only question that remains is whether the ASZ engine can handle 10W40 oil.

I've also done some benchmark tests to compare them with the current state.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

It looks better now, especially the acceleration from 90 to 210 km/h in 6th gear in 50 seconds .

I suppose it's normal for some residual boost pressure to remain at high engine speeds when releasing the accelerator pedal, right?

"The intake air temperature is alarmingly high, but it's the same as with ulf's original Poldi setup, showing a 67K difference above the outside temperature. I'll see if I can get more airflow through the intercooler without having to remove the fog lights."

rope wrote:

The only question that remains is whether the engine can handle 10W40 oil.

So then: Happy searching for this viscosity with VAG-PD approval .

Quote:

I've also done some comparison tests with the current version to see how it performs. It looks better now, especially the acceleration from 90 to 210 km/h in 6th gear in 50 seconds

Yep.

Quote:

I think it's normal for there to be residual boost pressure at high RPMs when releasing the throttle, right?

Yep. But (for those who are picky *lol*), it can be eliminated through a software change.

Quote:

The charge air temperature is alarmingly high, but it's the same as with ulf's original Poldi, at 67K above ambient temperature. I'll see if I can get more airflow through the intercooler without having to discard the fog lights immediately.

Good luck and the necessary perseverance in doing so.

That's what happens when you drive a car for four years without paying attention to it and only take it to the workshop for servicing and tire changes.

Seat doesn't have any specific oil viscosity requirements, and therefore I already have a 5W40 oil (VW 50501) in it .
This might explain the almost negligible oil consumption of approximately 0.2 liters every 10,000 km – that's equivalent to a small shot glass of oil every 1,000 km.

I only had to top it up once at a mileage of 10,000 km, and since then I've only checked the oil level every few weeks (which further reduces oil consumption, because I no longer wipe the oil dipstick ).


Regarding the intercooler, I had the idea to modify the air outlet slots in the wheel arch.
Possibly cut a large hole and cover it with wire mesh to protect against stone impacts.
However, in the winter, it throws salty slush into the engine compartment, which isn't ideal either.
It doesn't seem possible to enlarge or optimize the air intake without making other, more drastic changes to the front bodywork.

Does a decrease in the LLT (presumably "lowest loss threshold") of, for example, 10K actually have a noticeable effect?
I would estimate the power increase to be at most 1-2 horsepower.

rope wrote:

Does it actually have a noticeable effect if the LLT (Long Liquid Term) decreases by, for example, 10K? I would estimate a maximum of 1-2 horsepower more.

Yes: in the height of summer, when the engine reaches its maximum power for only a few seconds before entering the "fuel reduction" protective mode, it may be able to run at a lower LLT (Low Load Torque) with full power - if the reduced LLT is below the activation threshold of the fuel reduction function.

hi, a newbie needs help again .
I need some confirmation or different perspectives from you all .
"I've noticed that on my AVF engine (96 kW, manufactured in March, variant), the maximum torque or turbo boost seems to build up very slowly, well above 2000 RPM."
Thanks to the commercial VCDS software, I was able to take measurements on cylinders 3, 8, 11, and 13, as well as perform performance tests on cylinders 5 and 6. The results indicate that, as far as I can tell, the lambda sensor readings are above 1200 mg under load at 3000 RPM. Fortunately, the pre-detonation values are well below 1.2, ranging from 0.6 to 0.7, which is all good. However, since this "problem" started, the engine has been noticeably producing more soot under load. I should also mention that a particulate filter is installed.

Unfortunately, I don't have a comparable value right now, but the data confirms my feeling that there's a delayed power build-up with a slight dip after 2000 RPM and stronger performance starting around 2500 RPM.
My suspicion is that there's a problem with the VTG (Variable Turbine Geometry) adjustment. But before I disassemble and verschandeln the turbocharger, I wanted to ask: If there were a leak in the vacuum line, would the engine still be able to achieve its full power output?

Okay, and finally, the logs from the MWB devices.

If this log isn't useful, I can gladly run another one. Unfortunately, the test track I chose was rather short.

thank you

Best regards,
Harry

Hid3ki wrote:

Specifically, I've noticed for some time now that in my AVF (96kW, manufactured in 03, variant), the maximum torque or turbo boost pressure seems to build up very slowly, well above 2000 RPM. ... However, the car has also been noticeably producing more soot since this "problem," and it does have a particulate filter installed, just to be clear. My assumption here is that there's a problem with the wastegate valve adjustment, but before I disassemble and verschandeln the turbo, I'm asking again: if there were a leak in the vacuum line, would the engine still achieve full power?

It depends on how large the leak is.

Delayed ignition and excessive soot typically indicate a boost leak (especially if the air mass calculation shows unusual values).

These problems, combined with unknown tuning software, make diagnosing the issue a complete gamble. Many tuners allow for significant black smoke during turbocharger spool-up in order to get it working as quickly as possible.
However, if the full boost pressure is not achieved at some point (e.g., due to a small bite mark from a weasel), the engine will constantly produce black smoke even without a turbocharger leak, shortly followed by the overheating variable turbine geometry (VTG) seizing up, and a major turbocharger failure is imminent. If enough compressor debris makes its way into the cylinders in the process, the entire engine may be beyond repair.

"I just removed the engine cover and I think I found the problem; it was probably my own fault. I had sealed the EGR valve with a piece of metal back then. After removing the trim, I saw soot, and when I looked at the turbocharger (VTG), which was being moved back and forth by VCDS to its default position, I also smelled a strong diesel odor. Upon closer inspection, exhaust gases are escaping from it. Worst case scenario, the manifold has a crack, but that will become clear."

Let's see .

edit:

"The manifold has a long crack, running from the turbo flange all the way up to the exhaust outlets. I'll replace it tomorrow and verschandeln the turbo while I'm at it."