AFN Turbocharger Adjustment Mechanism

Hi,
I've had an AFN engine in my T3 for about 110,000 km. The engine had 40,000 km on it before I installed it, so the total mileage on the engine is now 150,000 km.
"About 50,000 km ago, I had to replace the turbo because the adjustment mechanism was completely corroded. Okay, that was probably my own fault, because the turbo spent one winter exposed to salt spray and had to endure some tough off-road driving with a lot of mud."
Now, this stupid adjustment lever on the new turbo is broken again!
This charger, with its 50,000 km, has had a rather peaceful life. No salt spray (the undercarriage protection is tight), no mud battles off-road. Why is this stupid thing already again?
Can anyone recommend a good repair shop that can get the adjustment working permanently? Are there any improvements that can be made to prevent it from seizing up again?

Regards,
Jens.

Hi Jens,

du hast den Turbo gewechselt, weil der VTG Mechanismus hing? It turned out to be unnecessary.
You can disassemble, clean, and reassemble the turbocharger without affecting its balance. The shaft remains untouched. Disassembly and reassembly are very simple. Otherwise, the larger vacuum actuator is better than the smaller one.
Giving it a little full throttle on the highway helps with fixed VTGs. Otherwise, Russ makes the mechanism difficult to operate. That would also be the permanent solution. Every now and then, full throttle .

Regards,

Maciek.

Maciek wrote:

A little full throttle on the highway helps against fixed VTGs. Otherwise, Russ makes the mechanism difficult. That would also be the permanent solution. Every now and then, full throttle .

Hi Maciek,
Okay, here's the translation:

"I'm copying my post from the Bulliforum here so that other readers can have the same information."
Please provide the text you would like me to translate from German to English.
Okay, while the issue of "over-revving" at full throttle might be true, I can't find any correlation with my own driving habits. I often drive with a heavy trailer (2 tons). Since the camper van itself weighs 2.4 tons (without luggage), I'm usually driving around 4.8 tons (with luggage). With this weight, there's really no other option than to accelerate fully even on the slightest incline. So, I'm just going to boldly assume that the full-throttle percentage of my T3's engine is much higher than it could ever be in a normal car! Therefore, I can't follow your recommendation anymore; it's already part of my everyday driving.

In my opinion, converting a T3 to a TDI engine is only worthwhile if the following conditions are met:
- The driver is a professional mechanic and handles the conversion and all related work himself.
- The vehicle's availability isn't really important, meaning occasional downtime due to maintenance and repairs is acceptable.
- Money is no object (don't tell me that converting to a TDI engine would be economically viable, it just won't work, not even if I do the work myself).

Regards,
Jens.

Hi Jens,

Take a look at the vacuum pump, or completely disconnect it (mark the length of the VTG rods, you'll probably need VAG-COM for fine-tuning later).
By simply unscrewing the can attachment without the rod, you can also check where the problem lies: is it the can itself or the VTG (Variable Geometry Turbine) adjustment? A small amount of copper-based assembly paste applied where the VTG adjustment lever enters the turbocharger won't hurt.

If dirt gets in where the rod goes into the container, it will quickly affect its smooth operation. If it gets stuck, disassemble it, fill the container with diesel using a syringe (be careful not to damage the membrane inside), and flush it thoroughly, moving it back and forth.
Unfortunately, I still haven't found a source for new vacuum tubes.

If your turbocharger is not working properly, it could also be due to the engine producing more exhaust smoke than usual when running at full throttle. Is the intercooler piping sealed properly? If the engine has been tuned, is it also necessary to increase the turbo boost pressure?

Best regards, Rainer.

Rainer K. wrote:

If your turbocharger is sticking, it could also be due to the engine producing more than usual black smoke when running at full throttle. Is the intercooler piping sealed properly? If the engine has been tuned, is it also beneficial to increase the turbocharger boost pressure?

Hi Rainer,
The engine is in its original condition, so it hasn't been modified. The only issue is that the EGR valve has been mechanically defective for 100,000 km. I haven't noticed any excessive black smoke under full load yet.
I'm going to take the turbo apart and disassemble it. Do you know of a good solvent to remove the old carbon buildup from the turbine side and flush it out? If the turbo is already disassembled, that would be a good time to do it.

Regards,
Jens.

Hi,

Quote:

Do you know of a good solvent to dissolve and flush out the old carbon deposits from the turbine side?

If the turbo is already removed, that would be a good opportunity.
"With my replacement loader, it worked quite well with diesel/gasoline, and the soot was removed effectively."
I wouldn't recommend scraping at the wheels.

Best regards, Rainer.

Hi there.

After the company Schlütter was unable to deliver a VNT15 turbo (where I had initially sent it), I sent the defective turbo to STK. Incidentally, the diagnosis was identical at both companies: very high bearing clearance in the shaft, the turbo is no longer repairable. Unfortunately, it wasn't the adjustment mechanism . STK had a VNT15 in stock, which I installed.

Now it's running again, the Syncro.

Here are two more positive things I'd like to share:
"The engine control unit must have been going crazy because of the turbo. I have to give the electronics a lot of credit for that! With a purely mechanical TDI, I might have eventually taken the turbo apart and run the individual pieces through the engine (with the corresponding consequences) because there was nothing to hear or feel. Eventually, the compressor wheel would have disintegrated, and the pieces would have ruined the engine."
HERE is an advantage of "sensitive" tax programs with control loops.

"During the last turbo failure, I replaced all the screws with V2A stainless steel screws (and lubricated them with high-temperature ceramic paste, which is important!). I also replaced the bolts connecting the exhaust manifold to the cylinder head. Unfortunately, I also had to remove the exhaust manifold because the one non-V2A stainless steel connection was stuck. It was the bolt on the flange between the turbo and the exhaust manifold, which I had left as the original. As a result, I couldn't remove the (V2A stainless steel) nut and had to remove the entire exhaust manifold along with the turbo. However, it wasn't a problem thanks to the V2A stainless steel screws. You can't really get to that stupid nut easily anyway (poor design)."

The three V2A stainless steel screws for the exhaust and the two between the manifold and the turbo came off without any problems. You can clearly see the effects of high temperatures on the V2A stainless steel screws. According to metallurgical theory, V2A becomes brittle at high temperatures and is therefore supposedly unsuitable for such connections. This may be true, but I have never been able to remove the supposedly "suitable" copper-plated screws/nuts that VW uses after a longer period of operation. They are always completely rusted and almost impossible to loosen. Since none of the V2A stainless steel screws I used showed any signs of fatigue fracture, it seems that it actually works. This test has now been running for over 50,000 km and two winters with a lot of salt.

My exhaust system is a custom-built one. In the front section, after the turbo, I used V2A stainless steel bends from the industrial piping industry, and from the flexible section onwards, I used what are supposedly stainless steel exhaust pipes from HJS. The flexible section (also from HJS) and the HJS pipes are rusting (forming brown iron oxide)! The flexible section, especially at the transitions from the stainless steel mesh to the pipe, is rusting quite heavily. The flexible section is definitely not made of stainless steel. The V2A pipes from the piping industry are significantly darkened, but they show no brown rust. They are clearly much more corrosion-resistant than the (alleged) stainless steel exhaust pipe from HJS.

Okay, that's all for now...

Regards,
Jens.

Hi Jens,
It's a popular 'trick' in the exhaust industry...

Stainless steels, which are allowed to be called 'stainless' according to the standard, do not necessarily have to be rust-proof.

http://de.wikipedia.org/wiki/Edelstahl

'My exhaust system even used stainless steel pipes... and then it was...'
fused together with ordinary welding wire

Best regards,
Rudi