AVF Issues: Causes, Symptoms & Treatment

Hello everyone,

Today, I drove my new Passat AVF for the first time on the highway. It ran quite well, but the acceleration wasn't as impressive above 140 km/h. Starting around 3800 RPM - approximately 180 km/h, it started to jerk sporadically. The highest speed I reached (due to heavy traffic) according to the speedometer was 215 km/h, although there were still a few more km/h potentially available.

This evening, I used VAG-Com to read the error codes. The result: 0 errors.

After that, I took a closer look at the MWB 23 and 28 models.

MWB 23:

1 cylinder - 0.7
2 cylinders - 0.4
3 cylinders + 0.7
4 cylinders + 0.4.

MWB 28

1 cylinder - 13.0
2 cylinders - 13.0
3 cylinders - 15.0
4 cylinders - 7.0

It actually looks quite normal, doesn't it?!

Where does the stuttering/jerking come from then?

Best regards, Dieter.

The problem is that your measurement data, as they are, don't really tell us anything relevant to your problem.
But it doesn't matter.

Possible causes for a malfunctioning PD (Pressure Distributor) could include: fuel supply leaks, a dirty filter, leaks in the distributor itself, and many other issues that can be found through research in this forum (e.g., contact problems with the PD).

And one more tip: When a problem starts to appear on the horizon, why try to push through it at the very limit? Would you run a marathon while you're sick?

@matthiasTDI96: Why do these data readings tell us nothing?

It's not what you might call "full-throttle," because it only occurs in the highest gear under full load, and only starting around 3800 RPM.

And whether I chose to keep my foot on the accelerator despite the engine jerking at around 3800 RPM is really my own business - Should I have just pulled over to the shoulder immediately??

Of course, I spent about an hour searching and reading various posts, but I couldn't find a comparable problem.

I don't understand why you're arguing so aggressively right away?

"I'm having a problem that VAG-COM isn't immediately showing, and I'm also reading two control module codes (23 & 2 due to a suspected issue with the high-pressure pump (PDE). I have a simple question."

Und dann so eine Antwort.... It's really sad.

I wonder why forums even exist if you can't get a reasonable answer to your question.

I'm a little confused about the MWBs right now... I wonder if those are...
Weren't 013 and 023 the numbers you had?
I'm having trouble with the 28-inch [item], or does the Passat have something that our A4 doesn't?
doesn't have?

Well, it's a matter of interpretation...

In reality, there's probably a middle ground between doing absolutely nothing and going all out... but whatever.

I also felt that my answer contained some interesting ideas. However, since there have been an incredible number of responses posted in a very short time, it's possible that other writers share similar views.

@vagtuning: of course, MWB 13 and 23. Unfortunately, it was prescribed incorrectly.

It seems like I'm not making any progress this way...

I thought the problem could somehow be contained, but unfortunately, I was wrong.

I'm going to do a log drive this weekend... it seems like there's no other way.

Why don't you address the points mentioned by Matthias first?

I also don't understand why you are immediately so aggressive in your arguments??

'I'm having a problem that VAG-COM isn't immediately showing, and I'm also reading two control module (control unit) codes (23 & 2 due to a suspected issue with the high-pressure pump (PDE). I have a simple question.'

Und dann so eine Antwort.... It's really sad.

Ask me why forums even exist if you can't get a reasonable answer...

You can convince yourself of a lot of things . Less caffeine and a little more relaxation helps .

Hi Rainer,

because I can rule them out.

The jerking only occurs in 6th gear and under full load, starting around 170 km/h.

Why only in 6th gear?!

Dieter W. wrote:

The jerking only occurs in 6th gear and at full throttle, starting around 170 km/h. Why only in 6th gear???

"Jerking" is a highly complex phenomenon, depending on the cause: "Flexible" components in the powertrain (e.g., dual-mass flywheel, tires, engine mounts) can exhibit varying degrees of oscillation, depending on their internal damping characteristics. Even the individual oscillation properties of these components can result in a complex overall oscillation behavior that is difficult to predict.
If the vibration damping parameters in the MSG software are not appropriately configured within these frequency ranges, the entire system can experience noticeable vibrations even without specific defects – sometimes selectively in certain gears or load conditions/speed ranges, depending on the play in the transmission gears, the wear condition of the dual-mass flywheel, the engine mounts, or even the softness of the tires. There are cases where the vibrations disappeared by switching to different/new tires .

In other words, it takes a certain amount of luck for a TDI engine to never exhibit any hesitation or jerking, even under normal operating conditions and with higher mileage.

You can therefore disregard all the points I've posted without even looking at them. You seem to be quite talented. However, I find it strange that you're just throwing in eight measurement values and not even coming up with the idea of creating a log file in the problem area, even though the necessary equipment is available.

Even if you think I'm talking nonsense, I've included meaningful suggestions in my post. However, you're hiding behind your own logic. This way, you can dismiss everything I'm saying, because your problem only occurs in the 6th gear above 170 km/h. So, WHAT are those measurements for then????? Huh?

matthiasTDI96 wrote:

So, you can exclude all the points I've posted without even looking at them.

You seem to be really talented.

matthiasTDI96 wrote:

I wrote that I can rule out the 3 points you mentioned because I had already checked them. But you just post things to the forum without thinking.

Just throwing in eight measurement values like that, and not even independently coming up with the idea to create a log in the problem area, especially when the corresponding equipment is available, I find quite strange.

Sure, I'll do another test run at 10:00 PM tonight... That's really funny.

matthiasTDI96 wrote:

Even if you think I'm talking nonsense, my post contains meaningful suggestions. However, you are hiding behind your own logic. IN THIS WAY, you can dismiss everything I write, because your problem only occurs in the 6th gear above 170 km/h.

I only called you aggressive... and now you're acting like a lunatic?

matthiasTDI96 wrote:

What are the measurements FOR, then????? Huh? }

...I had already written this, the initial suspicion was PDE, which is why I took those measurements!!!

Please just provide the translation... I don't like pointless discussions about principles.

@ulf: Thanks for your objective response. I will explore various options in the coming days and hope to eventually eliminate the issue.