Turbocharger Valve Check: How To?

Hello,

I don't want to be idle during these two weeks of waiting.
Does anyone have any idea how to check the valve for the turbocharger pressure regulation? I tried replacing it once with a used part, but who knows if that part wasn't also defective...

Thank you and best regards.
Wool.

Hi.

Since the control mechanisms for wastegate and VTG (Variable Turbine Geometry) chargers are different, the valves also operate differently.

That means that without knowing the engine type, no one can give you reliable advice.

Hi Ulf,

Thank you for the information.

Okay... it's a 5-cylinder AEL engine with 140 horsepower and a 2.5-liter displacement, manufactured in 1996.
Unfortunately, I don't know for sure...SHAME , but it would probably need a VTG charger.
The valve has two vacuum hoses and what appears to be a 2-pin connector.
If any information is missing, I'd be happy to check the car.

See you then.
Wool.

Hi.

Quote:

So.....it's a 5-cylinder AEL engine with 140 horsepower and a 2.5L displacement. It's a 1996 model. Unfortunately, I don't know for sure... SHAME, but it should have a VTG loader.

Soon, I'm going to give up trying to determine the charger type based on the engine ... I can't figure it out for anything with more than 4 cylinders.

Okay, here's the translation:

"So, here again is the helpful information:"
If one of the turbocharger hoses runs from "behind the turbocharger" through a valve to the turbocharger intercooler, it is a wastegate turbocharger.
If any of the hoses connected to the vacuum pump become detached, it's a VTG issue.

It took some time, but I'm back again...

My car is the odd one out, or maybe it's me (because of my lack of technical knowledge)... hehe.

Okay, to be completely honest... I'm not particularly knowledgeable about diesel engines. However, I have a basic understanding and I'm eager to learn, and I believe I'm capable of learning. So, if I sometimes express myself vaguely or awkwardly... please be patient with me. It will get better over time. I enjoy learning new things.

So, the turbocharger is (absolutely, without a doubt) a VTG (Variable Geometry Turbocharger).
I haven't been idle and have looked into the function of the VTG (Variable Turbine Geometry) charger. (Here in the technical section). The adjustment rod for the charger is housed in a casing in my car, which seems to have an oil line connected to it. Furthermore, it appears that this casing also has cooling fins.
Therefore, I can't see the rod. However, when I apply suction to the corresponding vacuum hose, it feels like the resistance increases and then reaches a maximum. When I then release the suction, the whole process reverses. Based on my feeling, I would say that this is normal.
The part number for the turbocharger should be 046 145 703 G. I read that from a riveted identification plate.

The part number of the affected control valve is 034 906 283, and it does not have an index.

Das Regelventil hat übrigens nicht 2 sondern 3 Unterdruckschläuche. Ich habe es an der Spritzwand gelöst und siehe da.....den Schlauch an der Unterseite des Ventils hatte ich vorher nicht gesehen. SoI'm sorry.

The LLK also has two vacuum hoses, one at the inlet and one at the outlet.

In my opinion, there's quite a bit of greasy, but mostly dry, soot buildup in the hose that connects the turbocharger to the intake manifold.
To the point where something might occasionally "come loose" or "fall off."
Since I can't lift the car onto a lift, it's only resting on the ground.
I was only able to detach the hose from the side of the collection suction tube. Just mentioning that for informational purposes.

Okay, it's your turn again. I would be very happy to hear something new.
THANK YOU IN ADVANCE!!!!

Regards,
Wool

Let's see if I can still manage it:

Remove the valve and hold it with the hose connections facing downwards. Place your mouth on the OUT connection and suck, you should feel air flowing in. Then, block the ATM inlet --> the valve should be airtight.

Apply pressure to the valve and then vacuum at the VAC connection: air must flow in. Turn off the power --> the valve must seal quickly and completely.
Turn the power back on, vacuum, and keep the OUT connection open --> Valve closed.

If the valve behaves significantly differently, it's likely defective. This is assuming it's the same type as the one used in the AFN (I don't have the part number handy, but it has a black plastic housing, and the cap with the VAC connection is gray).

Hi Ulf,

Thank you for your effort.

My valve is made entirely of metal. Too bad. But I'll try to see if it behaves the same way anyway. This might take a few days, but I'll let you know if I find out anything new.

Thanks again, and see you soon.

Regards,
Wool.

Hi.

Quote:

My valve is made entirely of metal. Too bad.

Hm, strange... as far as I know, the metal parts are only available on the older 66 kW 1.9 TDI engines with the wastegate-turbocharger (1Z, AHU). On those engines, the turbocharger is "conventionally" controlled with overpressure, which is varied by the solenoid valve.

It seems somewhat puzzling that a 5-cylinder engine would have a VTG turbocharger (which is normally controlled by vacuum), but also include a pressure-regulating valve.
But one never stops learning .

Hi Ulf,

I just called Audi. The result: The valve is indeed the correct one.
You can really rely on the fact that this is not a wastegate turbocharger.
Your effort in writing the description was not in vain. It would have been really annoying if that hadn't been done.
"That old valve costs about 75 euros. Man, that's not exactly cheap, but if it turns out to be the fuel injection pump that's making my car smoke... AAAAAARRRRGGGGHHHHHHH... that's roughly 1000 euros."
I should be able to provide more information about the valve by the middle to end of next week. In the meantime, I've definitely had some time to tinker with things again.
And in 2-3 weeks, I'll know more about the pump.
Dann melde ich mich wieder. It is promised.

Thank you and best regards.
Wool.