Hooray, it's working now!

Hello everyone,

Here's a brief report on the various factors that influence engine performance:

Letztes Jahr erwarb ich einen Passat Kombi EZ 01/99 MKB AFN Automatik mit 120TKM - bei der Probefahrt lief er ganz ordentlich. Leider hatte ich keine Vergleichsmöglichkeit. Einige Monate später hatte ich die Möglichkeit genau den gleichen Wagen (AFN/Automatik/EZ 11/98/126TKM) zu fahren und musste feststellen, daß dieser viel besser zog und ruhiger lief. Als erste Maßnahme war ich dann mal in einer Werkstatt (zum ersten mal seit Jahren!) - Fehlerspeicher wurde ausgelesen - ohne Befund! KCommentary from two workshops (Bosch and VAG) - that's normal: it's production variation!
Now, however, my ambition had been piqued – so I acquired some literature, bought a diagnostic tool with an adapter, researched tips and tools online, and even built some of the tools myself!

After that, I proceeded as follows:

1. The mass airflow sensor (MAF) was reading slightly below the expected values; it has been replaced.
Parts trading - the wagon was already pulling better.

2. Injector nozzles replaced - also sourced through parts suppliers.
The car pulled better and ran much smoother - also, it stopped smoking.
He doesn't even recognize her anymore.

Removed and thoroughly cleaned the intake manifold - it was [dirty/clogged].
pretty messed up - even with some success.

4. Then came a problem - at 95,000 km, there was an issue with a VAG vehicle.
Timing belt has been replaced (according to service record).
(Brochure) - For informational purposes only, I have reviewed the hiring process.
Camshaft checked and the results were shocking.
It was misaligned by approximately 8-10 degrees. I have now adjusted the wave correctly.
set and the start of injection was dynamically checked.
After that, the car ran quite well.

But I wasn't satisfied yet!

Ich arbeite seit über 30 Jahren in der Fliegerei und kenne die Produkte der Firma Garrett und die Qualität nun schon lange - unglaublich viele Steuerventile für Luft fallen an Luftfahrtzeugen aus weil die Membranen der Druckdosen weich werden ! Nach dem ich entdeckte das ein Garrett Lader verwendet wird, richtete ich meine Aufmerksamkeit auf dieses Bauteil. Obwohl der VTG-Mechanismus leichtgängig war reagierte die Druckdose verzögert. NAfter comparing it with the other car, I decided to switch brands – going with VAG. Unfortunately, they didn't have the part in stock; only a replacement turbocharger was available.
Thanks to Rainer K., I had the information about the part number and supplier (Schlütter/Cologne) - Thank you very much, Rainer!

Am letzten Freitag kam das Ding (156 € incl. VI'm sorry, but the provided text 'ersand)' is incomplete and doesn't form a coherent sentence or phrase in German. Therefore, I cannot provide an accurate translation without more context. Please provide the full text you would like me to translate.

I changed it on Saturday right away. The result was amazing – the car runs great now. Also, you can hear the turbocharger when starting up now, which means it spools up much earlier and provides boost. I could also hear that sound in the comparison car, but not in my car before!

This story clearly shows how a series of small errors can ruin the entire engine's performance!

The error memory was always empty – the errors were either purely mechanical or within the tolerance limits of the OBD system, meaning there were no recorded entries.

Prima !

But the praise for the VTG can part number should actually go to Ulf .

hi,
Please, please post the exact source and part number again. I know it's like "figure it out yourself!", but this is probably the first and last time I'll ask!
"thank you so much!" or "thanks a lot!"

Hi.

Quote:

The AFN series container 433483-1 can, for example, be easily replaced with the larger container (approx. 7.5 cm) No. 434855-3

. In this case, the larger heat shield No. R7026940001 should also be installed}.

(from the error database)

Source: see www.turbolader.com

Hello Ulf,

Okay, I'm ready. Thank you very much!

Jürgen.

And a thank you to the person who, with a lot of money and the help of people here (especially Ulf), figured out that it was due to the too-small pressure vessel and that there is a larger one available!!!! No, just kidding, don't think for a moment that I believe I am now the problem solver here, but I'm happy that this problem seems to be resolved, and that people who come here won't have to spend 1800 euros like I did (just thinking about it ), but will have the opportunity to fix it with less money!!!!
'@Ulf: I wanted to give you the number of my engine control unit, but I'm really busy right now. But as soon as I have time, I'll look into it!!'

Okay, I'd like to install a boost gauge in my car, mostly for fun. Does anyone know where I can find some that are relatively inexpensive? It's basically just a regular pressure gauge, right?

Hello Markus,

Just to clarify, my car already had the large pressure accumulator installed. In my case, the membrane inside was soft, which caused a delayed response. I was familiar with this problem from membrane-actuated valves in airplanes.
However, the main purpose of my report was to highlight that a gradual decline in engine performance can have a whole range of causes. Sometimes, it's unavoidable to first check the mechanical basics of the engine. In my case, the OBD system only showed weak readings for the mass airflow sensor.
Regarding fuel injectors: Based on my experiences, including those with vehicles owned by friends, I would consider the injectors a real weak point. In some cases, replacing them after 130-140,000 km has proven to be highly effective! Bosch also profits significantly from the replacement program. That's one of the main reasons why I won't buy a car with PD (common rail) injectors – they are even more expensive!

Hello Jürgen,

You've definitely given me a scare with that information about the injectors. I'm at 127,000 km now, and I really hope they, and the rest of the car, will last for a while longer. So far, though, there are absolutely no signs of any problems; the car runs like a dream, with top speed and acceleration just like it did from day one, etc. I'm actually considering selling it in six months, so ideally, it shouldn't incur any major expenses by then, but I don't really believe that will happen!
hello

Hello MarkusAFN!

Don't worry, my car still has the original tires, even though it now has 204,000 miles on it.
No problem.

Best regards, D.

Hello Jürgen!

Hello Markus,
Regarding fuel injectors: based on some experiences, including with vehicles owned by acquaintances, I would consider the injectors a real weak point. In some cases, replacing them after 130-140,000 km has had a significant positive effect! Bosch also makes a lot of money from the replacement program. That's why I won't buy any PD engines – those parts are even more expensive!

Has anyone you know taken a closer look at the injectors before returning them to Bosch? I'm curious if it's possible to see signs of wear on the injection pressure or spray pattern. Or were the injectors simply replaced as a precaution? (It's quite expensive for that...)

I just bought a set of used tires on eBay (supposedly with 87,000 km mileage) from a vehicle that was declared a total loss, and I'd like to know if they are actually better than my old ones (with 266,000 km).

Can you see anything under the microscope? I've read about abrasive wear, but I don't know if it affects the nozzle needle or the holes.
I'll go ahead and have the 'new' ones installed and let you know how it goes. I can keep the old ones and maybe even take them apart?

Regards,
Udo (A4, AFN engine, '96, 266,000 km).

Hello Markus, hello Udo,

also an den TDI Einspritzdüsen gibt es ausser dem Abspritzdruck nicht viel zu checken, gerade weil sie zweistufig sind. Wenn ich mir aber den Aufbau und die Funktionsweise der Düsen ansehe, ganz ich mir ganz gut vorstellen wie sie im Dauerbetrieb leiden. Für mich sind die Einspritzdüsen ein eindeutiges Verschleißteil unabhängig davon wie lange sie halten können. Der Verschleiß und die damit einhergehende Verschlechterung der Motorcharakteristik sind schleichend. Im RThe change only becomes apparent after the initial adjustment period, which is a perfectly normal process of getting used to things.
Ich selbst habe in den letzten 5 Monaten an 4 Fahrzeugen - Passat AFN, Golf AHF und T4 AHU die Düsen gewechselt - alle zwischen 127 und 142TKM und zwischen 2 und 3 Jahren - in allen Fällen war die Wirkung beindruckend (Anzug/Motorlauf/Rußverhalten) - danach habe ich mir das testen lassen gespart - es macht auch keinen Sinn die Dinger selbst zu zerlegen. In zwei Fällen war Verdacht auf defekten Nadelhubgeber, der sich auch bestätigt hat. Da alle 4 Fahrzeuge für ihr junges Alter sehr hohe Laufleistungen haben, was auf häufiges Fahren mit hohen Geschwindigkeiten schließen lässt, sehe ich da einen Zusammenhang (Hohe Dauergeschwindigkeit = steigender Verschleiß!). AucSeveral mechanics (who should be taken with a grain of salt) told me about numerous nozzle replacements.
I actually just wanted to point out with my comment that, based on my experience, the mechanical parts of the engine and the fuel injection system should be considered first.
Such complex electronic systems in a vehicle typically require that the mechanical parameters are correct. I've seen this behavior in diagnostic systems used in aviation (e.g., Airbus): It can happen that an electronic error message leads you in the wrong direction because, for example, some mechanical setting is incorrect.

Sorry, Markus.
I didn't want to scare you. If your car is running well, then everything is fine, especially since you plan to sell it. I just wasn't satisfied with my own car, and the results confirm that my actions were correct!


Regards,

Jürgen (a notorious workshop skeptic!)