1,9er PD mit EU4: warum meistens so kompliziert? | Posts 16+

ulf wrote:

The maximum possible number of errors in a system increases with the number of its components. Therefore, a simple system is inherently more reliable - if it is designed and built with the same care as a complex one.

So, a PD engine must fail three times more often than a VP37, because the PD has four injection pumps compared to the VP.

Well, I highly doubt that .

In addition, the PD TDI is significantly more complex than the VP TDI. Nevertheless, it does not have a higher failure rate.

Quote:

For me, "reliable" is definitely more important than "just new" without an objective increase in usefulness - but it seems I'm quite alone in that opinion

.

Basically, I agree with that as well.
Even when I initially upgraded from the ATD to the AXR engine, I had my own concerns. However, experience has shown me that this engine was noticeably more reliable.

Furthermore, what could be worse? The AGR system in the AXR engine at least has the advantage of not getting as clogged. If the cooling switchover stops working, there's neither an error message, nor is there a noticeable difference in performance. The DK (direct cooling) system performs its function just like the pneumatic AK (air-cooled) system. In my opinion, there's no difference in complexity.


@Goettmann
As far as I recall, in the AXR, the DK (damping coil) is also pulled closed by a spring force and opened by magnetic force, similar to the quantity adjuster in the VP37. So, the system is essentially the same, but the control method is different.

Hello, since you're talking about DK here - my sister drives a Polo 6N SDI from 1998 with a pneumatic AGR-DK.

Recently, she called me and asked if it was possible that her car was in a fault mode, which she had noticed for a few hundred kilometers and which was getting progressively worse...
The explanation was that the engine is very loud and runs sluggishly, but the check engine light isn't on!
And she's coming, and I need to take a look at it sometime this weekend.
I already let her drive almost 100 kilometers, even though she was having stomach pains.

It was immediately apparent upon opening the hood that the loud engine noise was coming from the throttle body. With the intake hose disconnected, it was possible to see the throttle valve fluttering, although it appeared to be moving freely. When the connector was disconnected from the solenoid valve, the noise stopped.
I then eagerly took it for a test drive, but it was still very sluggish, as my sister had described, although the engine noise was no longer abnormally loud.
The error entry indicated a faulty throttle position sensor (TPS) with intermittent interruptions.
In the rearview mirror, there was no one visible. Also, the air and fuel filters are only a few thousand kilometers old.

By now, it was Saturday afternoon, and the end was in sight.
The membrane of the vacuum sensor on the DK unit was torn, causing it to draw in air. This resulted in the DK unit vibrating at the clocking frequency and being unable to be controlled correctly.
Due to the lack of intake manifold vacuum, the EGR system and oil mist separator from the crankcase ventilation system have been working effectively.
The intake manifold, the curved plastic intake pipes, and the intake manifold flange looked like the inside of an old two-stroke exhaust pipe.
Of the 4th cylinder's bore, perhaps only 30% remained, the rest was a pulpy mixture of rust and oil that transitioned into a hard crust towards the cylinder head.
2 hours of cleaning work is not enough!

Since replacement parts were no longer available and nothing suitable could be found, I sealed off the vacuum connection to the DK (distributorless ignition coil) and the EGR (exhaust gas recirculation) valve.
Result: The Polo is now running smoothly again, and there are no error messages.

Now the question arises whether the DPF (Diesel Particulate Filter) may have been defective for much longer due to the immense contamination of the intake passages, or whether the EGR (Exhaust Gas Recirculation) system in the SDI engine is inherently so ineffective?
Do you think that the exhaust back pressure could also force open a well-sealed EGR valve, and that using a 'shim' would be the best solution?

Best regards,
Daniel.