TDI - Leistungsverlust ab 3000 u/min | Posts 16+

Hi,

What exactly is broken inside the turbocharger? Could it just be a faulty variable geometry turbine (VTG)? I'm interested to know.

Best regards,
René K.

the turbo itself has excessive play in the shaft; it's a miracle that the blades haven't been damaged by contact with the walls yet .
If I touch the wave on the leeward side and the windward side, I have approximately 2 mm of play .

and unfortunately, not adjustable via the VTG setting...
Well, as I said, a new one has already been ordered...
By the way, the pole is incredibly smooth and easy to operate! There's no snagging or jamming!

Hello,

Quote:

the turbo itself, the shaft has way too much play; it's a miracle that the blades haven't been eaten away by the walls yet

.
It's no surprise given the absolute boost pressure of 1.5 bar that you measured.

Note: a worn-out turbocharger is very likely not the cause of excessively high boost pressure!
The only potential source of error that I can imagine for this issue with the turbocharger is a stuck variable geometry turbine (VGT) adjustment mechanism.

A new turbo seems like a very expensive "trial and error" approach to me.

Regarding the play: axial or radial? A small amount of radial play is normal because the shaft is centered by the oil pressure within the bearings. However, 2mm seems excessive to me. There should be no noticeable axial play.

Regards, Rainer.

PS: If the VTG adjustment on the turbo wasn't the cause and you continue to drive with excessive boost pressure, the new turbocharger will quickly look like the old one.

I can't really believe that it's solely due to the turbocharger, but all other components seem to be okay?
As I mentioned, the valve timing adjustment is easy and moves freely, and the valve itself is in good condition.
I don't know where else to look!
'The turbo isn't just a guess; it's clearly failing. Of course, the new one will break again if the boost pressure remains too high, that much is obvious. But the old one needs to be replaced anyway. As soon as the new one is installed, I'll immediately measure the boost pressure again. If it's still 2.5 bar at 3000 RPM, then...'
I'm going to talk to the workshop that serviced the car previously. It's possible that the faulty part was already replaced by the previous owner, but for cost reasons, or because it wasn't noticed, the turbo itself wasn't replaced.
As mentioned before, the strut of the VTG is in good condition; there are no signs of clamping or snagging.

Hi,

Have you ever considered sending that thing to a turbocharger specialist for inspection?
It could be significantly cheaper if it's still repairable.

Best regards,
René K.

Sure, but as mentioned above, the used car warranty comes into effect because the car was likely sold with or due to this problem. Therefore, the insurance will cover it, and a new charger will be provided. If we're going to do something, let's do it right .

Okay, I somehow missed the part about the warranty.

I hope that the new loader solves your problems and doesn't create any new ones for you...

Rainer K. wrote:

Note: a worn-out turbocharger is very likely not the cause of excessively high boost pressure! The only potential source of error that I can imagine for this issue with the turbocharger is a jammed VTG adjustment mechanism.

Hi everyone,

I can only agree with Rainer on that.

Although I would still investigate the cause further, specifically looking at the vacuum control system, including the solenoid valve and control lines, because I suspect that the maximum pressure will be similar after the turbocharger replacement.