Chip Tuning, K&N Air Filter, No Power Gain

Hi zusammen. Bin neu im Forum. Greetings to everyone!
Okay, so I wanted to get my diesel engine running smoothly. I had Inmotion-Tuning-at modify the 90 HP AHH engine to 120 HP and 280 Nm. I was completely satisfied with Ciptuning. But then: I, being a perfectionist, installed a K&N air filter and cleaned the mass airflow sensor (MAF). The next time I started the engine, my diesel was just a sluggish mess. I did some research in a forum. I bought and installed a new MAF sensor from DC, but there was no improvement, except that the engine only came back to life above 3000 RPM. Then, on a highway drive, I got the full chip-tuning power again, but only until the next exit. The same problem. Is there a limp-home mode, and how long does it stay active?
Conclusion: Never touch a running system!! What did I do wrong?? Or was it just bad luck that another problem occurred??!!

Update: At a mileage of 14,000 km, the turbocharger failed at a speed of 180 km/h on the highway. I called my workshop and was told I could drive the car to the workshop, since the catalytic converter was already defective anyway!! It was billowing smoke, so I drove to the nearest gas station, added the correct oil from a 20-liter container (getting long-life oil was still a problem back in early 2001). The workshop said that the exhaust system and the catalytic converter needed to be replaced (under warranty). I now have my doubts about that! } Current mileage: just under 80,000 km. Oh yes, when the car was brand new (company car), it was very fast. I thought I had a 100 HP engine under the hood, but according to the vehicle registration, it wasn't. When I asked the mechanic about it, he said that the variable turbine wheel adjustment was always at its maximum! This is why the turbo 'died.'


Thank you in advance to the forum for their efforts.

Hi Kurt,

Hello Kurt,

dieselross wrote:

I learned a lot in the forum. I got a new LMM from DC and installed it, but there was no improvement, except that the engine only came back to life above 3000 RPM.

Oh, you haven't done your research, have you? The mass airflow sensor isn't cheap, and replacing it without a diagnostic test is a risky and expensive gamble.

dieselross wrote:

Then, on a highway drive, the full chip-tuning power again, but only until the next exit. Same problem. Is there an emergency mode, and how long does it remain active?

Your problem description is far too vague and unhelpful. How exactly did the performance loss manifest itself?
At what RPMs, immediately after starting, does it only run at full throttle?
What other unusual observations can you make, such as excessive black smoke, a noticeable engine noise, etc.?
Of course, there is a failsafe program, but it is always activated with an entry in the engine control unit's error memory.
-> Read this out immediately after the error occurs.

Best regards, Rainer.

@Rainer
Hi Rainer, Okay. I'm not very knowledgeable about diesel technology. Well, trash can... Here are a few more details: The mass airflow sensor from DC is still affordable at 76 euros (compared to over 200 euros from V.A.G.). I probably damaged the original (Bosch) while cleaning it.
'On the first occurrence, the engine hesitated and only reached 2000 RPM. If you kept the accelerator pedal fully pressed for a few seconds, the acceleration would suddenly resume, but not with full power. This happened every time the engine was restarted.'
2. Installed a new LMM (Pieburg). It also only started to build boost hesitantly and it wasn't until around 3000 RPM that you could feel the turbo boost again, up to about 4500 RPM.
3. Currently, it's running as if I no longer have a turbo: it takes a long time to get going, and the top speed is only reached on long stretches of highway (approximately 180 km/h slightly downhill). Occasionally, you can feel that it wants to accelerate again from 3000 RPM, but then it 'falls' into a power dip.
4. I couldn't observe any smoke, either at idle or during acceleration. In first gear, the engine still revs up relatively quickly. However, it takes longer in the higher gears. And when accelerating, you can hear a strange 'knocking' or 'clunking' sound (especially with a warm engine).
I added a postscript to the first post.
I don't want to go to 'Zum Freundlichen' (a local car dealership) because of the chip tuning and the mass airflow sensor (MAF sensor) from DC. They probably wouldn't understand, since I didn't have the right special Torx screwdriver with a hole, so I had to 'loosen' the screws with pliers. I'll probably finish building my half-finished OBD adapter so I can test things myself.

Hi Kurt,

Hello,

Quote:

When I inquired with the master mechanic, he said that the variable turbine wheel adjustment was always at its maximum! This, he explained, caused the turbo to "die."

If you're not driving with your eyes closed and a brick-like foot on the accelerator, you'll notice this pretty quickly: as soon as the target charging pressure exceeds a threshold set in the control unit, the emergency program is activated, along with a corresponding error message. At the same time, a significant loss of power is noticeable.

To intentionally damage a turbocharger with a malfunctioning variable turbine geometry (VTG) system requires a significant amount of effort and time, and in my opinion, it's unrealistic.
Before we delve any deeper into this, let's go through the following points:
http://www.dieselschrauber.de/vptdifehler.html
http://www.dieselschrauber.de/tdischlauch.html

and for understanding.
http://www.dieselschrauber.de/vtg.html

Best regards, Rainer.

Hi,

To me, the description of your turbocharger issue sounds like a pressure hose has come loose or there's a larger leak in one of the hoses (perhaps it burst). It then appears as though the turbocharger is "broken" because the built-up pressure is no longer reaching the engine, and it's also making a whistling noise because the mass airflow sensor is measuring more air than is actually reaching the engine.

The turbo won't break down like that.

First, continuing to drive on the highway causes the EDC to detect insufficient or no pressure, the VTG to fully open, and the turbocharger to spin excessively, attempting to create a dust cloud in the engine compartment.

If that's really how it was, then the advice from your workshop caused the turbo to run at maximum boost the whole time... it was running with the variable turbine geometry (VTG) at its maximum setting, but due to the leak, not due to a defect.

Setting the VTG to its maximum setting would likely very quickly lead to an emergency situation because the pressure would become too high. Therefore, I believe the competence of that workshop is highly questionable.

Best regards,

Jan.

@Jan6K
Hi, all's well. My diesel engine is roaring back to life and running smoothly again!
It was actually a vacuum hose. I just connected it, and everything started working again.
But the annoying thing is: I had changed the air filter, and in the process, the hose must have come loose, probably not completely at first, which explains the short, fast highway drive. (It's about 4mm in diameter and is precisely inserted into the hose guide on the air filter housing, so it's not easily visible). I secured the culprit with a cable tie so that this kind of mishap can never happen again!

Thank you again.

Hi Kurt,

Hi,

Thank you for the flowers... but you've basically misunderstood me completely .

I was merely referring to the turbocharger damage that occurred at that time, which I attributed to a leak in the PRESSURE section (i.e., one of the large pressure hoses).

That the current problem was due to a vacuum hose... well... that's an example of a fitting misunderstanding .

Best regards,

Jan.

dieselross wrote:

@Jan6K Hi, all's well. My diesel engine is roaring back to life and running smoothly again! It was actually a vacuum hose. I just plugged it in, and it started working again. But the annoying thing is: I had changed the air filter, and in the process, the hose must have come loose, probably not completely at first, which explains the short, fast highway drive. (It's about 4mm in diameter and is precisely inserted into the hose guide on the air filter housing, so it's not easily visible). I secured the culprit with a cable tie so that this kind of mishap can never happen again! Thank you again. Hello Kurt

Great, thanks for the feedback!