Boost Valve Polo BLT TDI, Up to 2 Bar

Hello everyone.

While looking at a log of intake air temperature in another forum, I came across some extreme values in the log file. For the sake of completeness, I'm posting it here again and would appreciate any advice. Ulf has already given me some tips in the other forum.

1. Inspect VTG rods.
2. Check the solenoid valve.
3. Go to the friendly store and have everything exchanged (with a hint of irony).

The diagram shows overpressure up to 0.7 bar...
So, in total, up to 3 bar (1 bar atmospheric pressure + bar of boost pressure), which should be 2.35 bar...

The engine is not tuned; we were able to determine this based on the injection duration and a comparison of OBD diagrams, thanks Ulf! (You never know what previous owners might have done.)

What do you think about this, and do you have any other tips, or should I just accept it?

Is that normal behavior for the BLT TDI engine in the Polo?

Quote:

1. Inspect VTG rods. 2. Check the solenoid valve

.

What has been done so far in this regard?

Then read this: https://community.dieselschrauber.org/en/viewtopic.php?t=12979

To assess the boost pressure behavior, create a log file from MWB 10.11.

Record the data for 3rd gear (full throttle) from 1100 to 4000 RPM.

Hi, I'll be able to make it this afternoon.

Best regards,

Wurschdler wrote:

Hello, I will be able to come this afternoon.... Regards

It appears that the only way to access the VTG rod is from below.

Hello Wurschtla!

Autoservice wrote:

...To assess the boost pressure profile, create a log from MWB 10.11. Record the data from 3rd gear (full throttle) from 1100 to 4000 RPM.

Just do what he says for now...
Then you might not need to mess around with the VTG at all .

Best regards from Munich!

Quote:

...To assess the boost pressure profile, create a log from MWB 10.11. Record the data for 3rd gear (full throttle) from 1100 to 4000 RPM. Just do what he says for now... Then maybe you don't even need to mess around with VTG. X

First, check if the VTG is moving mechanically (I thought it was already happening). If something is stuck or jammed from the beginning, you can skip the measurement process. Just like you wouldn't check the air pressure in a flat tire.

Okay everyone, my problem is the following:

Unfortunately, I can't completely remove the loader because it's still under warranty.
To check the VTG (vehicle registration document), I would have to do that, but I can't even reach it from below.
Not even on the sides...

So, we're waiting for the loader to crash or we're triggering the error until something is stored in memory...

Then off to the...



Does anyone know a friendly and competent mechanic in the Nuremberg area?
If it weren't for the warranty, I would have already taken matters into my own hands .....
I know of one person, but I'm not sure if they handle warranty claims.

The VW dealer from whom I purchased the vehicle is unfortunately very competent .
(I hope you understand what I mean.)

There used to be a very competent person in Emskirchen a long time ago... unfortunately, they moved their residence... }

Quote:

Unfortunately, I can't remove the entire charger, because I still have a warranty on the car... To check the VTG, I would have to do that, but I can't even reach it from below.

You should first just determine (check) whether the plunger of the vacuum sensor moves freely when it is supplied with vacuum, and nothing else.

If necessary, use a mirror.

Wurschdler wrote:

Unfortunately, I can't completely remove the entire loader, because I still have a warranty on the car... To check the VTG (vehicle registration document), I would have to do that, but I can't even reach it from below. Not even on the side...

I don't know how it looks with the BLT and the AGR cooler, but with the ASZ Polo without a cooled AGR, you can somewhat easily reach the VTG rod from above with the engine cover removed (by threading the arm between the intake manifold and the injector nozzle). This way, you can also test with downward finger pressure whether the VTG is sticking in the open range of its adjustment range.
Maybe it works for a BLT too?

Okay, thanks, I'll try it right away...

No change... unfortunately.

The vehicle is too heavily modified. Not even a man with extremely small hands would be able to fix it...

Check the pressure difference with vcds in the default setting.

RedR32 wrote:

Check the pressure difference with vcds in the default setting.

It has just happened.

The difference between the VTG position "on" and "off" is 150 mbar.
Should be fine.

What is not okay:

The loader is making a very loud noise.

Edit:

In the log file, you will first find the data related to the accelerator pedal variant, and further down, the log data for the basic settings of the MWB 11.

Edit: Graphically represent the table.

168 mbar, which I think is a bit too high. Has anyone adjusted it? We should compare it to something.

Hello everyone!

@Red
Basically, up to 200 mbar, it's completely within the green zone. Also, the curve looks quite smooth .

@Wurschtla
How much discussion and data traffic is still needed before something effective is uploaded?
No offense, but - for the second time: Please create a full-throttle log, as Uncle AutoSchrauBär recommended.
It's not relevant to problem-solving whether you do it tomorrow, if you don't have time right now, etc. Just do it and then upload it, okay?
THEN we can help you!

Best regards from Munich!

DieselBär30x wrote:

Hello everyone! @Red Basically, up to 200 mbar, it's completely within the green zone. Also, the curve looks quite smooth . @Wurschtla How much discussion and data traffic is still needed before something effective is uploaded? No offense, but - for the second time: Please create a full-throttle log, as Uncle AutoSchrauBär recommended. It's not relevant to problem-solving whether you do it tomorrow, if you don't have time right now, etc. Just do it and then upload it, okay? THEN we can help you! Best regards from Munich!

Ok will be done, and where he is right, he is right.

The curve of the second log of the VTG basic setting is not as smooth as the graph above. In the attachment, you will find a comparison between Log 1 VTG and Log 2 VTG. So, I won't bore you with any more graphs! I promise.