VW Passat 3BG 1.9 TDI: Power Loss Troubleshooting

Hello dear members!

I'm new to this forum. I've been reading for a long time, but due to some issues, I need to post something now.

I have a VW Passat 3BG, 96kW, AVF engine, SG6 (FRK) transmission, manufactured in August 2003, with 185,000 kilometers on the odometer.
'For some time now, I've been experiencing a noticeable loss of power. The 'PD-Bums' sound has completely disappeared, and there's hardly any power, even at high RPMs. Thanks to this great forum, I first purchased VCDS from a member here to help diagnose the problem.'

To illustrate the problem, I measured the acceleration using KPower: The average acceleration from 0-100 km/h is 14 seconds, and the top speed, after a long run-up, is 185 km/h.

What I have already checked:

LMM:
- First, it was flushed with brake cleaner, but that didn't work.
- Installed a new LMM, but there was no noticeable improvement.

Charge air duct:
I connected the system with drain pipe fittings and checked for leaks. It maintained a constant pressure of 0.7 bar (unfortunately, I couldn't get it any higher).

Vacuum hoses:
I checked them with syringes, and they are leak-proof.

Turbo:
- Intake hose removed and the shaft checked for play, none found.
- With the vacuum hose disconnected from the vacuum actuator, the VTG linkage moves down about 1 cm quickly, but then moves back up slowly, almost jerkily - is this normal?

AGR:
The AGR (Abgasrückführungssystem) has been closed for quite some time, but I still checked the intake passages. They are all clear.

Kat:
The cat is securely fastened; we've already checked it because there was a suspicion that it might be loose.

From 1700-1900 RPM, a quiet noise (which some describe as a whirring or rattling sound) can be heard coming from the engine compartment. This noise becomes briefly louder when the accelerator is released within this RPM range, and then disappears. It is no longer audible with the window open.

Using VCDS, I logged some values according to instructions found on a forum.

Here's my guess: It could be a lack of diesel, a faulty tandem pump or a defective common rail injector, or the turbocharger might be failing. The oil consumption is 0.5 liters every 8000 km.

I hope you can help me.

Regards,
Sascha.

3bg-fahrer wrote:

...but slowly, almost jerkily, back up -> normal?

No, and that's your problem. The log clearly shows it.

Oh dear, I was afraid of that. What would you recommend: should I renovate and verschandeln it, or should I just invest in a new one?

Best regards,

3bg-fahrer wrote:

What would you recommend: renovate and verschandeln it, or invest in a new one right away?

I would first expand and verschandeln it. You can always buy new ones later.

Hey diesel mechanics,

I hope I've found the right topic...

I have the feeling that my Passat doesn't always want to accelerate properly... The engine was completely replaced 3000 km ago, the PD injectors were cleaned and are working well (idle speed control), the turbocharger has been rebuilt, the dual-mass flywheel is new, and the clutch is new...

I have VCDS available. Which blocks should I log so that you might be able to see something noteworthy?

Thank you in advance.

When I read

Quote:

turbocharger is refurbished

, is that the key point?
where I stop reading.

Okay... why?
Unfortunately, that doesn't help me with my problem.

Because, apart from the manufacturer, hardly anyone is able to service the chargers.
to restore them so that they behave 100% like the original.
That makes troubleshooting a real shot in the dark.

If the device is then operated with modified software, there's only one thing to do.
Unfortunately, I don't have a crystal ball.

If it were my car, I would first remove the modifications and then see...
whether the error still occurs.