AFN VTG 96: Stuck Valve - Troubleshooting:(

Hello everyone,

'I've been experiencing problems with the engine's performance for months, and yesterday I discovered that the variable turbine geometry (VTG) is quite stiff in the lower range. When you slowly pull the control lever, it gets stuck, and then suddenly jumps towards the maximum position. I then removed the vacuum actuator (the smaller version) and manually moved the linkage -> it's actually quite jammed. Attempts to restore some smoothness by quickly moving it back and forth have failed.'
Can the charger be safely disassembled and cleaned by the user, or is specialized equipment required for this?
I would be very grateful for your tips.

Best regards,
René K.

Hi.

You can read about my related troubles in the error database, and my final solution = a larger battery pack.

It's been working perfectly for about half a year, and that's why it's my best recommendation for other victims of VW's "banana politics" (where the products "ripen" after the customer buys them...).

Hello,

Thank you for the tip about the large can. However, €120 is quite a lot, and I'm a bit skeptical that the large can will help much, since the pole is quite stuck .
What about cleaning the turbo? Is that something that can be done easily? Or do you have any idea what it would cost to have it cleaned by a repair company?
Thank you in advance.

Best regards,
René K.

Hello René,

Are you sure the problem is with the adjustment mechanism in the charger itself, and not just with the adjustment shaft where it enters the turbocharger housing?
If you disassemble your charger, a report of your experience would be appreciated .
You can find pictures here that hopefully will help you understand how to disassemble it.
http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html
At least with the loader shown in the picture, cleaning is possible without disassembling the loader shaft.

Best regards, Rainer.

Hello,

'I tinkered with it again yesterday. It only seems to stick when it's in the resting position, but otherwise it's working pretty well. Unfortunately, my attempts to unscrew the pressure capsule were unsuccessful. It seems the workshop that tried to fix it two years ago might have welded it in place – at least, I can't get it to budge.'
So, I placed a few washers (approximately 3mm thick) between the pressure sensor and the bracket and then re-tightened everything. This prevents the sensor from regulating the control rod in that extremely sensitive range. The initial test drives went quite well. The car now has proper boost again and doesn't go into limp mode, even with brief overshoots to 1.3 bar. The boost pressure now regulates very quickly, settling between approximately 0.90 and 0.95 bar.
I hope this lasts for the next 140,000 km (that's how much it has now), because I'm not taking it to the workshop anymore.

Best regards,
René K.

zzzZZ wrote:

I tinkered with that thing again yesterday. It only sticks when it's in the resting position, but it's working quite well otherwise. My attempts to unscrew the pressure capsule unfortunately failed. The workshop that tried to fix it 2 years ago probably welded it in place - anyway, nothing moves.

Hi René,

The issue with the clamp being in the zero position was also my main problem.

From your description, I understand that you are unable to loosen the threaded rod, which is obviously frustrating.

Have you tried turning the lock nut the right way and holding the part on the loading side with something?
(It might be a silly question, but sometimes problems are solved this way.)

Hello,

I think I turned the lock nut the right way, and of course, I held it steady. It doesn't seem like the nut is the most stable part – I slipped with the wrench once, and now it's almost completely rounded, so I can't get a grip on it anymore. But it doesn't really matter for now, since the car is still running great.
Yesterday, I also did the penetration test (old values in parentheses):

Without tuning: 6.1 seconds (6.5 seconds, if it hadn't stalled).
with tuning: 5.4 seconds (5.8))

'6.1 seconds seems a bit fast, doesn't it? Could it be that the car is already so well-tuned from the factory?'
It's also pleasing that the turbo boost pressure now remains constant and no longer drops intermittently (e.g., at 2500 rpm) as it did before. At the same time, it now reacts much more spontaneously to movements of the accelerator pedal, and the power delivery is immediate. However, I'm a little worried about the transmission, as with the activated tuning, you can feel the strain on the drivetrain between 1500 and 2000 rpm. Normally, I only use the extra power in exceptional situations.
I can only hope that everything stays this way.

Best regards and many thanks to everyone... René K.