Ladedruck, VTG, Rückschlagventil... ich versteh nix mehr

[Translating...]

Hallo und schönen Abend,

ich habe immernoch (siehe auch https://community.dieselschrauber.org/en/viewtopic.php?t=17411) das Problem dass mein Golf IV (110 PS TDI, BJ 7.98 ) in den Notlauf geht. Grund dafür ist ein permanent zu hoher Ladedruck.
Nachdem ich per VagCom die Gängigkeit überprüft habe und die Unterdruckschläuche schon ein paar mal kontrolliert habe, habe ich mich entschlossen komplett neue Schläuche zu kaufen.
Habe die dann heute montiert und fahre los. Eigentlich funktioniert alles astrein, nur ab 3800 U/min. geht der Ladedruck dann doch etwas zu hoch (ca. 0,3 bar).
Wollte dann mal sehen ob die VTG noch gängig ist (Grundeinstellung), allerdings hat sich nix bewegt, Grund dafür war dass kein Unterdruck am Turbo ankam.
Naja, also habe ich dieses Rückschlagventil mal umgedreht und ich hatte wieder das alte Problem. Schon am 1500 U/min. ganz bös zu viel Ladedruck, der sich auch nach Gaswegnahme nicht einregelt (bzw. sehr sehr langsam).
Dabei hatte sich die VTG allerdings in der Grundeinstellung bewegt.

Wieso ist das so, dass mein Ladedruck eigentlich astrein (Solldruck = Istdruck) aufgebaut wird, obwohl ich keine Verstellung sehe und auch keinen Unterdruck fühle?
Eigentlich müsste der sich doch verhalten, als wäre er im Notlauf, obwohl er perfekt beschleunigt.
Bin nun vollkommen verwirrt und hoffe, dass mir jemand helfen kann.

Besten Dank im Vorraus und einen schönen Abend.

Sven

Hello, I had a similar issue. There was a vacuum hose running behind the diesel filter towards the turbocharger. Check if it wasn't pinched by the diesel filter. I had done an inspection at the time, and after that, the engine was only running at 50 horsepower! Then we checked the hoses and the VTG (Variable Turbine Geometry) could no longer be moved (due to the vacuum). After we had adjusted the filter and re-routed the hose, everything started working as it should again.

As I understand it, you mean the hose that goes directly from the boost control valve to the turbo's pressure housing. I replaced that hose, among others, yesterday. And, as I said, the strange thing is that I'm not experiencing any noticeable loss of power, which is illogical. I'll try driving without the hose later. Was if there was a topic where someone had similar symptoms due to a poorly assembled turbo?

Is it possible that a removed VTG shovel produces so much suction that the turbo becomes uncontrollable, but there is too much pressure when the other shovels also engage?

Space for a tax arm to retract seems to be present in the turbo:


m;

Yes, that's definitely possible. As I said, I found a similar post. I will link it later (I have it at home).
It seems that the adjustment ring was installed incorrectly, which also caused it to get stuck. Unfortunately, I don't have a stage and also no garage, which makes expanding the turbo quite complicated.
However, I have been looking for a used turbo for quite some time.
The turbo now is basically a refurbished one, and you shouldn't really expect such things.

Here is the link: /viewtopic.php?t=4969&postdays=0&postorder=asc&highlight=rückschlagventil&start=24

Unfortunately, the images and logs are no longer available. Would definitely be helpful.

Greetings

Sven

Hello,

ATL with the hanging shovel arms was actually produced from the factory. Some were delivered in this way, but it's moving within the PPM range.

This error can only occur during assembly. Once the ATL has been properly assembled, the "blade arms" will no longer come out of the pockets of the adjusting ring. If your engine was running properly at some point, don't assume that you won't experience problems like the ones you had from the beginning.

Why can the repairman do it better? There are only people working there.

Greetings

Andreas