Turbo Problems? Get Turbo Repair Help Now!

Hello everyone! My A6 2.5 TDI (110 KW + Pbox) has been at the VW dealership for 14 days. Initially, there was 'only' an oil leak, which was fixed thanks to tips from this forum (the strainer of the crankshaft ventilation was leaking). The oil was also leaking under the turbo at the return line (seal). When they removed the turbo, they told me it was worn out. So, I bought a new (used) one. It made a great impression. After installation, the car goes into limp mode at full throttle. 'Boost pressure limit exceeded.' The printout showed 3 measurement blocks (target and actual pressures). All 3 values were significantly too high. The master technician searched for a while and then told me that the delivered turbo was broken 'because this didn't happen with the old turbo'!? I then read here in the forum that the VTG rod should be extended. The technician has now done this, but unfortunately without success. Now, I'm supposed to supply or buy another turbo. My question: Can the turbo or the VTG itself really be defective? Or is it a regulation problem? I'm desperate and don't want to buy a new turbo based on suspicion! Thanks for your help!!!

bdsf2003 wrote:

During the overhaul, I was told that the turbo was worn out

.
Did you experience any problems with the emergency mode before?
I somehow got the feeling that they were looking for a way to earn some extra money.

bdsf2003 wrote:

Can the turbocharger or the VTG itself really be defective?

If the turbocharger bearing is defective, it will consume a lot of oil, and the shaft will likely have excessive play (a small amount is normal). Alternatively, the turbine blades may be rubbing. The variable turbine geometry (VTG) could be stiff, but it is easy to check by hand.

Hi Wolfi, who is happy about his first star .

Okay, so the old turbocharger had some excessive play and some oil in the compressor housing. Therefore, I should replace it. The new turbocharger was inspected by me and the mechanic beforehand and was found to be absolutely okay. The wastegate is operating smoothly, and the pressure sensor is moving the linkage. The master mechanic says that perhaps the mechanism inside the turbocharger is defective, which is why the control system isn't working = too much boost pressure. Does 'regulation limit exceeded' always mean too much pressure, or could it also indicate too little pressure?

Hello,

For a quick check of the VTG's maneuverability, I have the following note:

'Both my old turbocharger and the new one, as well as one other...'
The VTG rod on the display stand for the TDI engine was barely visible, even with a thumb.
to move a few millimeters. Were all three of them stuck, or is it normal for them to do that?
Is it that difficult?

How much force should one be able to exert when manually pressing something, if everything is working correctly?

What force is required to do that?

Regards,

Bernhard.

Hello Bernhard,

The difficulty encountered was due to the spring force of the vacuum chamber. Therefore, a manual check using a VTG (Verband der Transportwirtschaft Güter) chamber can only be performed with a syringe or similar device to create a vacuum.

Yesterday, I disassembled a turbocharger and cleaned the variable geometry turbine (VGT), which was actually quite easy.
And after I had cleaned everything, you could push the lever from one side to the other. It moves very smoothly.
And the pressure canister, when it was removed, could also be pressed all the way in with my hand (just like that) .
In the built-in state, it is only about 4mm .