Air Supply 1.4 AMF

I've become curious again and have a question: My 1.4 TDI PD (AMF) has a small "branch" with a diameter of almost 2 cm on the air intake pipe between the air filter and the turbo. The pipe leads up to the engine (where the PD injectors are located, or near the camshaft; it looks like a crankcase ventilation system). There's an electrical connector and a connected vacuum hose on this branch (which probably controls opening or closing something). What is the purpose of this connection?

Thank you for the information.

Regards,

Olaf.

P.S.
Okay, and one more thing:
Two vacuum hoses connect to my VTG turbocharger. One goes to the pressure sensor for the VTG mechanism. The other ends somewhere near the bottom of the turbocharger (unfortunately, I can only feel it). What could it be used for?

Hi!
I have the same engine in my Polo. The electrical connection on the ventilation system is a heater that prevents ice (from condensation) from forming in that area during the winter, which could block the ventilation. Unfortunately, I can't tell you what the remaining vacuum connections are for, because the turbocharger in the Polo is completely hidden, and you can't see anything. Oh yes, when does the valve in the crankcase ventilation system close? Is it definitely a valve?

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

"Dirk"

No, you're right, it's probably the heating system and not a vent... That was nonsense what I wrote there.
Unfortunately, my charging station is also completely blocked. This, unfortunately, also means that I cannot properly test the functionality of the VTG (Vehicle-to-Grid system). That's really a pain, because I'm occasionally experiencing problems with the turbocharger boost control.

Regards,

Olaf.

Hi!
I didn't mean to criticize you about the valve. You're right, both electrical wires and pneumatic lines connect to this thing. I just wanted to point out that I'm absolutely not sure what the vacuum line is for. I'm really curious about it. If there's a valve inside, when does it close, and why? Maybe someone else in this forum knows the answer?

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

"Dirk"

Olaf wrote:

Two vacuum hoses connect to my VTG turbocharger. One goes to the pressure sensor for the VTG mechanism. The other ends somewhere near the bottom of the turbocharger (unfortunately, I can only feel it). What could it be good for?

Hi Olaf,

Perhaps it would be insightful to know where the other end of the mysterious tube is connected.
Take a look over there (if that's not also blocked).

All three of the vacuum hoses in question connect to the different sides of the well-known N75 solenoid valve.

Regards,
Olaf.

Hello,

This has been discussed in the forum before. Already searched?

Unfortunately, this also results in me being unable to properly check the function of the VTG. That's really a pain, because I'm occasionally experiencing problems with the turbocharger boost control.

Regards,

Olaf



Hello Olaf!
It's unlikely that the VTG (Variable Turbine Geometry) is the cause of the intermittent issues you're experiencing with the boost pressure regulation. Unfortunately, the AMF only has a single turbocharger with a wastegate.
The hoses consist of a vacuum line (from the vacuum pump to the solenoid valve) and two pressure hoses (from the pressurized side to the solenoid valve, and from there to the control valve).
There is actually no vacuum hose connected to the crankcase ventilation system. Could it be that the hose is connected to the shut-off valve?


Klaus.

This has been discussed in the forum before. Already searched?

@Michael II

That's news to me, but definitely not this year! What search terms are you using? Sure, here's the translation:

"A link would be nice."
@Klausi
Contrary to the official VW information released when the engine was launched, the AMF engine actually has a VTG turbocharger. However, the data sheets have now largely been corrected by both Volkswagen and Audi.
No, the hose for the shut-off valve is a different one.

Regards,

Olaf.

Olaf wrote:

>This has been discussed before in the forum. Already searched? @Michael II That's news to me, but definitely not this year! What search terms are you using? Sure, here's the translation: "A link would be nice." @Klausi Contrary to the official VW information released when the engine was launched, the AMF engine actually has a VTG turbocharger. However, the data sheets have now largely been corrected by both Volkswagen and Audi. No, the hose for the shut-off valve is a different one. Regards, Olaf

Just for information, since this post is 20 years old, most people probably already know this, but no, an AMF definitely does not have a VTG loader .