Polo 9N3 (1,4l TDI PD) springt schlecht an, nach Standzeit | Posts 112+

It should be there; please refer to the measurement blocks from the combination instrument.

Best regards, Rainer.

dieselschrauber wrote:

It should be there; see the measurement blocks from the instrument cluster. Best regards, Rainer

Ah, dashboard! Great, thank you very much!

I have now found the measured oil level in document MWB 07.

However, the reading has been showing the exact same value for days, even when I'm interacting with the car: 63.5mm. According to VCDS, this is the value from the TOG sensor.

I also have the feeling that the oil level is increasing slightly.

Is this value truly reliable according to the MWB 07 standard?

Quote:

Is this value really reliable according to MWB 07?

Good question...

In my opinion, the sensor is mainly intended to provide a warning when the level is too low.

Best regards, Rainer.

Brief update:

After approximately 3,000 kilometers, the oil level has increased by about 2 millimeters.
So, it seems there's another small leak again.

Okay, here's a translation:

"Now, a question to clarify something: how does diesel fuel get into the engine oil? Is one of the three seals responsible for this, right? But where is the contact point with the oil circulation system?"

And could I now identify the responsible PDE element using VCDS?

Generally, I would continue driving as usual with more frequent checks. After all, new oil will be added at the latest after 27,000 kilometers. What do you think?

All the possible causes are listed there.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.



One thing at a time; eliminate possibilities one by one!

Best regards, Rainer.

stolley wrote:

Generally, I would continue driving as usual with more frequent checks. After all, new oil will be added at the latest after 27,000 km. What do you think?

Change the oil after 15,000 km; the camshaft and the rest will THANK YOU for it.

Hey Stolle,
Could you please create a log of the MWB (Motor Warm Betrieb - Engine Warm Operating Condition) for the 23rd? Or even better, a log that combines data from cylinders 13, 18, and 23. The engine should be warm, and let it idle for about half a minute. Also, give it some short bursts of throttle once or twice, and record the results.
If it were to escape from the return flow, you would see it that way, but unfortunately, you don't even see that. It's just an attempt. Don't bother trying anymore.

Steffen W wrote:

Hi Stolle, Could you please create a log of the MWB (Motor Warm Betrieb - Engine Warm Operating Condition) for the 23rd? Or even better, a log that combines data from cylinders 13, 18, and 23. The engine should be warm, and let it idle for about half a minute. Also, give it some short bursts of throttle once or twice, and record the results. If it were to run away from the return flow, you would see it that way, but unfortunately, even then you wouldn't. It's just an attempt. Don't bother trying anymore.

Thank you for the tip!
I'll try it out and post about it!

Okay, here's the log I promised.
What does that mean to you?

This is a BWB engine with fast-acting 1.5 common rail injectors. However, it seems to be experiencing issues that cause the fuel pressure to drop as low as 87. I would generally recommend having the fuel supply checked.
Please have the pre-charge pressure of the tandem pump measured using a pressure gauge, according to the instructions. Also, measure the flow rate of the pumping unit in the tank.
It just takes a clogged filter like the one mentioned in Bolzer's thread.
Regardless, you can also try logging the initial engine speed. Find a relevant measurement block (MB) in control unit 01 that displays the engine speed, disconnect the common connector for the pump injectors at the cylinder head, and check the reading. It should be 280 RPM.

Steffen W wrote:

This is a BWB engine with fast-acting 1.5 injectors. But it seems to be dropping to -87 in certain areas. I would generally recommend having the fuel supply checked. Please have the pressure of the tandem pump measured using a manometer, according to the instructions, and also measure the flow rate of the pumping unit in the tank. It just takes a clogged filter like the one mentioned in Bolzer's thread. Regardless, you can also try logging the initial speed. Find a relevant measuring block (MB) in control unit 01 that displays the speed, disconnect the common connector for the pump injectors at the cylinder head, and let it hang. You should get 280 RPM.

"I'm sorry, I didn't express myself clearly."
The startup issue has been resolved.

Even so, the engine oil level is slowly but steadily increasing. That's why Steffen W suggested logging the data using the MWB 13-18-23 parameters – oh, that was you!

Did we just completely talk past each other?

I actually didn't read that he's having a great start right now.
"None of the injectors are malfunctioning; they all operate at the same speed. This is the only diagnostic information you can gather when searching for faulty PDE (positive displacement element) zero rings."

Sure, I'd be happy to translate the text from German to English for you. Please provide the text you would like me to translate.
If, for example, you were to read values of around -90 on one cylinder, while all the other cylinders are reading approximately -10, then either the piezoelectric element (PDE) is defective or the zero ring in the middle is damaged. This means that fuel is flowing directly from the high-pressure side to the return side on that particular cylinder. However, this doesn't seem to be the case with you.
I would still recommend having the pre-injection pressure of the tandem pump checked. Diesel can potentially leak from there into the oil. Because it's cycling so quickly on all the common rail injectors, I suspect there might be a general fuel supply issue.
However, if one of the sealing rings that prevents backflow is leaking, the oil level will also rise, and the engine will run normally.
Unfortunately, this type of defect cannot be detected using the relevant diagnostic equipment.

Hello everyone!

My reliable three-cylinder engine has now covered over 60,000 km since the new injector seals were installed.
Now, the timing belt needs to be replaced. At the same time, I will take a closer look at the hydraulic lifters (as a reminder, they showed signs of wear during the sealing of the common rail injectors) and replace them if necessary.

Now, I would like to ask for your opinions on this:
Should I also re-seal the expansion joint during this process, or would it be better to leave it alone, following the principle of "never change a working system"?

Sure, here's the translation:

"Here are some additional background details:"
- The engine still starts up really well.
- There is still a slight increase in the engine oil level (but it remains at roughly the same amount, either high or low).
- I would like to drive the Polo for at least another 50,000 km.
I would be happy to provide the log files for the LRR if that helps with making a recommendation.

Sure, here's the translation:

"Thank you in advance!"

If it's not absolutely necessary, I would leave the threaded section as is, because the threads for the tensioning wedges are very delicate and not suitable for repeated loosening/tightening.

TDI-GTI-4-Motion wrote:

If it's not absolutely necessary, I would leave the PDE in place; the threads for the tensioning bolts are very delicate and not suitable for repeated loosening/tightening.

Hi, thanks for your assessment!