Air Mass Sensor Error: Passat PD 100hp

Hello to all the diesel mechanics!

I'm just not getting anywhere with this problem.

I'm not satisfied with the performance of my Passat PD 100 hp, which has the engine code AVB. The power drops off after 3200 rpm.

First thought: mass airflow sensor.

So, I ran the test, and bingo. Starting around 3000 RPM, the actual value no longer increases and remains at approximately 450.
Of course, I immediately installed a new one, but the values haven't changed.
The turbocharger pressure is normal.

What could be the cause of this, and can the diode trick also be applied to this motor? If so, which diode should be used, and how should it be connected?

I would be grateful for any help.

Regards,

Luke.

Luftfilter? Intake path?

Regards,

Manuel.

Yep, there's even a swimsuit in there.

I've already tried everything. I've even checked the exhaust gas recirculation system and made sure it's sealed.

What makes you so sure that it was the sports air filter? Is that thing clean? Read through the forum; those parts aren't necessarily the best choice for a TDI.

What makes you so sure that the boost pressure is correct? If the mass airflow sensor (MAF) is working properly and your intake path from the MAF to the turbocharger compressor is airtight, and the boost pressure is actually correct, then I don't understand it. That would be a contradiction in itself. What equipment/method did you use to measure/check the boost pressure? It's also possible that a faulty pressure sensor is the cause.

Hi,

@matthias

I was advised to try a K&N filter, but it didn't show any difference compared to the original filter, which was also new.


@joergs

I was using a Bosch diagnostic tool, and the actual and target values for the boost pressure were matching.
However, this was not observed during operation. That is, without any load, but across the entire RPM range. Only the LM (likely referring to a measurement like lambda or load) halved starting around 3000 RPM.

That's why I don't understand any of it.


Sure, then.

Luke.

Measuring boost pressure while the vehicle is stationary is tricky. Measuring boost pressure while the vehicle is in motion is essential.

Measuring the boost pressure while the engine is idling is tricky. Measuring boost pressure while the vehicle is in motion is mandatory.



ok,

I need to get a laptop first.

Or an LDA.

-A small tip: Read the technical article about air filters. Rainer put a lot of effort into it, and you can also benefit from his findings.

Yes, exactly, and that might apply to you:

Quote:

Furthermore, the installation of an open filter or a sports filter box can alter the airflow profile in the mass airflow sensor, causing it to report too little or too much air intake, which in turn disrupts the engine management system.

(as stated in the referenced article)

Yes, but with original air freight, it's exactly the same .

Therefore: either install an LDA (Lambda Damper), or perform a full load measurement using VAG-COM.

Perhaps checking the charge air duct for leaks and ensuring the VTG linkage is properly adjusted might also help.

oh
Then I'll join joergs.

Here's another tip: search for "diode test" within this forum; you might find ways to create a simple "dongle" for testing purposes.

Did someone overlook the search function again and is making others search for things instead?

Did someone overlook the search function and is once again making others do the searching for them?


No, that didn't really help me.


Oh, I see.

By the way, the consumption is also around 8 liters.