PD Motor Problems: Common Failure Causes

Hello,

the worn cam lobes in the case of long sleepers https://community.dieselschrauber.org/en/viewtopic.php?t=20201&highlight=.
Unfortunately, they fit so well with a topic I've found that I'd like to bring up the main points here for discussion.

Please provide the German text you would like me to translate into English. I will then provide the translation without any explanations.
I am sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the content of the provided URL.

Recently, an increasing number of camshaft defects are being discovered in pump-nozzle engines.

The damage pattern is usually the same: the cam lobes that actuate the valves wear down at the highest point, until the hardened layer is worn through, and the camshaft then makes contact with the hydraulic lifters.

. . . I have a faulty cylinder head lying around in the workshop; it came from a 115 hp PD engine.
At the highest point of the first valve tappet (exhaust valve 1), about 3-4 mm are missing. Of the tappet itself, only the cylindrical part remains; the contact surface is completely gone.

From my regular dealer, I know of at least 3 other cases that were repaired last year, including 2 ARL engines.

The repaired engines were all thoroughly serviced by VW.
You can also find reports of similar defects in various other online forums.
Some of them show significant signs of wear all over the shaft, not just on one cam lobe.

Bitte gib mir den deutschen Text, den du übersetzt haben möchtest.

Some people believe that this is due to the reduced additive packages in the 507.00 oils, which were changed because of vehicles with particulate filters. Therefore, it is 'allegedly' that the 505.01 oil is the better oil for the PD engine....

Do we have any more information about that within our team?

ulf wrote:

Bitte gib mir den deutschen Text, den du übersetzt haben möchtest. Ich kann den Inhalt dieser URL nicht abrufen und übersetzen. Bitte stelle den Text bereit, den du übersetzt haben möchtest.

"Unfortunately, you are not allowed to access this page. You do not have the necessary access rights to view this page."

pschaefer wrote:

"Unfortunately, you are not allowed to access this page. You do not have the necessary access rights to view this page."

I am aware of this. That is why I copied the main content above, so that everyone can read it without having to log in.

Hello Ulf,

The last PD TDI engine where I inspected the camshaft was an ARL model with approximately 166,000 kilometers. There was no sign of wear.

Best regards, Rainer.

I have a car with 207,000 kilometers on the odometer, and the engine looked very good recently during a PDE (presumably referring to a specific engine component) replacement. Everything seemed fine.
My parents have an ASZ model with 110,000 kilometers and an AXR model with 140,000 kilometers. There have never been any issues with either of them.

It's also possible that bees are dying due to occasional exposure to "non-PD oils," and that later, no one wants to know or be able to prove it, depending on their point of view.

teileklaus wrote:

It's also possible that NWs (presumably referring to a specific type of organism or entity) die due to occasionally "non-PD oils," and that later, no one wants to know or be able to prove it... depending on their point of view?

Of course, that is conceivable.
It would have been good to have this information available from the beginning. But just as the first refurbished engines (likely with a wastegate internal recirculation system) and the new oil suitable for diesel particulate filters had started to accumulate some mileage, reports of increased instances of turbocharger failures are (apparently) starting to surface again.

"In my opinion, this fits perfectly with the change in VAG oil standards to low-ash oils suitable for DPFs, which seem to be "certified" as PD-compatible almost as an afterthought, as the new oil standards include the old ones."

Here are the "best" pictures of the damage to the AJM, with the author's permission.

According to the oil theory, the engines that were "afflicted" with WIV oil meeting the 506.01 specification should then be experiencing increased wear.

The "DPF-compatible fluid" according to specification 507.00 has a better HTHS (High-Temperature High-Shear) value and should therefore help reduce engine wear. However, specification 506.01 has likely not been used anywhere for quite some time, as it has been completely replaced.

Regards,
Peter.

So, the error patterns shown here are all not typical of PD (Partial Discharge) and certainly not typical of diesel engines.
I'm also familiar with these kinds of issues from other types of engines.

If I want to attribute these types of damage to the 50700 engine, I also need to examine other components in the lubrication system that are subject to higher stress (connecting rod bearings, cylinder liners, PDE drive...). If the problem is due to the general oil quality, then I should see at least as many types of damage in those components as I see in the turbocharger.

The images shown here appear to me to be more indicative of prolonged lack of lubrication or, alternatively, serious material defects. The hardening process of the camshafts is not always optimal or consistent over a long production period. Small manufacturing tolerances, which can further exacerbate the problem, ultimately lead to the damage being almost inevitable.

The valve actuator should be able to function properly with any standard oil. This applies even to PD engines. I don't see any connection to the 50700 specification in this case.

Okay, I'm having the same problem, but it's not quite as bad. I've always used 5W40 505.01 Fuchs Titan oil, and I've driven about 210,000 km.
As the picture shows, the camshafts are surrounded by a chamfer. In my case, this chamfer is already missing, which results in a slight burr. However, the hydraulic lifters still appear to be in good condition.
I also have two PD heads lying around that show the same image, 'Grate' instead of 'Fase.' Everything else is still in good condition. However, I don't know the mileage of those heads.

EMSimASZ wrote:

.... I also have two PD heads lying around that show the same image. ...

I have 6 used injectors from gasoline engines that are showing similar error codes, and three more from common rail diesel engines, but only one from a pump-injector diesel engine.

I'm sorry, I can't see any connection to a PD motor there.

Welcome to the club .

Does the image suggest that the camshafts are narrower than those of a VP engine, like my old AAT?

christians wrote:

... Does the image deceive, or are the camshafts narrower than those of a VP, like the one on my old AAT?

They are narrower.

Basically, a connection is possible, but gasoline engines might be more stressed by the higher RPMs. However, this could be offset by a better lubricating film, which would also result from the higher sliding speed.
With the V6 TDI engines, the issue isn't entirely clear, but it's evident that weaknesses in the hardening process, design, or lubrication can quickly reveal flaws.

I recently saw a post in this forum about the 'redesign' of the oil circuit in PD engines.
gelesen: 'Ölfilter im Nebenstrom'. Vielleicht ist die Filterwirkung bzgl. Abrasion.
It is inherently weaker due to its design and causes such problems. Does the bypass system still exist?
Still ongoing in the CR?

Regarding camshafts, I was recently having a casual technical conversation with an engine builder.
gehört, dass der Verschleiß nicht immer gleich der Laufleistung gesetzte werden kann. Er
I was mainly referring to connecting rod bearings, but camshafts can also be significantly affected by low temperatures.
'The rotational speeds and the idle speed are suffering. He described it as wear only occurring under load.'
Motores an den Bereichen aneinander bewegter Teile 'weggespült' wird. Short without.
Regular stress and changes in speed lead to microscopic metal wear.
'It shows a higher rate of wear than what the mileage would suggest.' -> He gave one answer.
withdrawn, whether there is a connection to the newer oil specifications, as...
This would be specific to VAG.

Best regards,

neubaupe wrote:

I recently read something in this forum about the "redesign" of the oil circuit in PD engines...

This applies to all VW engines... including the gasoline engines that are based on the 827 platform.