PDE as Piston Splitter?

Hello,

Someone in the Fabia forum had the piston of someone else's ASZ engine, which had been tuned by Pbox, completely destroyed.
He suspects (after confirmation by several experts?) that a faulty PDE could cause something like that.
http://www.fabia4fun.de/thread.php?threadid=5131&sid=73cdf5cadbd9ae71f5b863bb48ff0f50

Then it surprises me that nothing has been explicitly written about this yet... who from our group can contribute something to shed some light on the matter?

Topics such as
Ich kann den Text nicht übersetzen, da ich keinen Text erhalten habe. Bitte gib mir den Text, den du übersetzt haben möchtest.
They don't specifically address PDEs as potential causes...

Of the photos linked on the Fabiaforum, only a few are sharp enough to be useful, so I've attached a selection here.

Hi Ulf,

Therefore, I will also have regenerated PD units available soon, as PD motors are simply getting old.
The test stand for the PD elements is under construction, although, if I think of some know-it-alls who believe that simply "screwing it on" is enough, I should probably just provide a 15mm wrench and say "it should fit" .

Best regards, Rainer.

Hi, a non-atomizing nozzle would melt a hole through the material. However, the pistons appear to be more likely to have failed due to overload. There might also be some slight play in the connecting rod bearings. The piston breaks off at the connecting rod pin.
Best regards,

kalle wrote:

Hi, a non-atomizing nozzle would melt a hole through. However, the pistons appear to be more likely to have failed due to overload. There might also be slight play in the connecting rod bearings. The piston breaks off at the piston pin. Best regards

In a private message, cupra_turbo (also known as Creative Cardesign in the Fabia forum) wrote to me:

cupra_turbo wrote:

definitely not the case... the connecting rod clearance was excellent and in order, the piston pin and the sleeve in which the pin sits were/are perfectly tight...

I assume he can't post here yet (no blue overalls).

We want to know, then, when the test stand is ready. Initially, there were still some "minor things to take care of," or...?

You could then also offer the tool kit for changing gears...

matthiasTDI96 wrote:

We want to know then, when the test stand is ready. Initially, there were still some "minor things to take care of," or...? You could also offer the tool kit for changing gears...

Anyway

Quote:

In the Fabia forum, someone apparently destroyed a piston from someone else's ASZ engine that had been tuned by Pbox. He suspects (after confirmation by several experts?), that a faulty PDE could cause something like that.

I personally don't believe that.
Because:

1. It almost always affects cylinder 3 or 4.

2. This is not a problem that is exclusive to PD engines, but also occurs in the 1Z and AFN engines.

3. In the case of cylinder head damage, cylinders 3 and 4 are always affected.

Therefore, my suspicion is increasingly leaning towards thermal overload.

If nozzle defects are the primary cause, then damage to pistons 1 and 2 should also occur, or...? Is it just a coincidence? I don't believe that.


It is conceivable that the injectors, specifically the pressure dividers (PDs) of cylinders 3 and 4, could be damaged as a secondary effect due to prolonged thermal overload.

Quote:

Therefore, I will also have regenerated PD units available soon, as PD motors are simply getting old.

That's great news. If only the price is right too...


By the way: VAG uses pistons from two different manufacturers in these engines, so it's also interesting to know whether both piston manufacturers are affected.

What could be the cause of the thermal overload? It's probably related to the cooling path of the water from cylinder 1 to 4, and then to the radiator. I can't think of much else. I also don't think it's likely to be due to the fuel pump, perhaps it's due to excessive combustion pressure, but even then, the fuel pump might not be the cause if it has to inject an impossible amount of fuel.

Quote:

What could be the cause of the thermal overload? Surely it's only due to the cooling path of the water from cylinder 1 to 4, and then from there to the radiator.

Possible. I definitely think there's a connection between the head gasket and the piston damage in cylinders 3 and 4. In the last engine I saw with a piston failure, the head gasket (possibly for a long time) was also leaking.

BM wrote:

1. It almost always affects cylinder 3 or 4.

Okay, so the Fabia is an exception here: in picture 1, you can see that it's the leftmost cylinder (when viewed from the front). This is the cylinder head side, and that's where the numbering starts, AFAIK -> Piston 1 is defective.

Or am I wrong?

@ Ulf,

Yes, but it also had its fuel injection quantity increased, which could lead to a possibility of excessively high combustion pressure.

matthiasTDI96 wrote:

yes, but that one also had fuel injection quantity increased: possibility of excessively high combustion pressure.

Hmm... apparently, the Pbox was supposedly tuned to around 165 horsepower.
Regarding the GT1749VB without any software adjustments: based on my experience, it likely delivered a similar amount of airflow as the ARL or BPX models in their stock configuration.

The start-up KF values for ASZ and BPX are identical, which means that the BPX can only "supplement" the ASZ, just like any other Pbox.
The engine blocks (including the pistons and therefore the combustion chamber geometries and compression ratios) of the ASZ and BPX engines are identical.

"Certainly, unlike with the BPX, the LLT (likely not far from 100°C) was higher, and presumably the box programming was in the mid-expansion rate range: it probably wouldn't have been satisfied with the approximately 58 mg of the BPX."

But considering that the BPX still has certain tuning capabilities, in this case, the evidence for the conclusion "damage caused by Pbox" seems a bit thin.

Hello!

Quote:

Approximately 108,000 km. I have to mention that I mostly drive on the highway, and I always try to get there as quickly as possible.

Thermal overload.

BYE
TDI mechanic.

Hello everyone,
I think it's more likely due to thermal overload. I also remember seeing various threads about it. In cases of engine damage, the pistons in cylinders 3 and/or 4 were often damaged, which could be due to the design of the channels or possibly due to deposits that build up in the channels over time.
The manufacturers are also different; I had to replace a piston, and the replacement piston I received was a Mahle piston, which weighed a whopping 40g less than the old one!
It seems that temperature is a crucial factor, and I believe that's why turbocharger failures are so common. As a result, the variable geometry turbine (VTG) is damaged, or the channels become clogged, which then leads to bearing damage...
All of this is more likely to apply to tuned engines due to the increased stress they experience.
I believe that PDEs (particle-depleted flows) are rarely the cause of such damage; the rotational speed would have to be far above 4000 RPM to reach the bursting range. At such high pressures, I also can't imagine that, for example, combustion residues could clog the nozzle holes.
However, it is possible for cracks or deformations to occur in the nozzle tip of the PDE (Plasma Dynamic Expansion) system, causing the beam to directly hit the piston, which would eventually melt the piston or cause the tip to burst.
That would be quite obvious...

*dust off*

I'm once again dealing with this topic (not out of my own initiative) and have been unsuccessfully searching on my hard drive for a .pdf document from a motor repair shop that contains numerous images of damage, including those of engine pistons, along with descriptions of the causes: melted pistons, fatigue cracks, etc.

Does that sound like a link to anyone?

Thank you...

Hello Ulf,

Do you know:
http://www.ms-motor-service.de/ximages/ks_50003801-01_web.pdf
Please provide the text you would like me to translate from German to English.

The fracture pattern on the damaged piston doesn't look good. In my opinion, several factors are likely involved, ultimately leading to material fatigue and cracking. In other words, the more "stress" the piston was subjected to, whether it was excessive peak pressures, uneven temperatures due to a poor fracture pattern, poor or inconsistent cooling, eventually a crack will form.

Ultimately, the quality of the piston itself could also be a potential problem. I know of at least one case where such damage occurred in an engine that was not modified and had only about 150,000 kilometers on the odometer.

Best regards, Rainer.