Geschwindigkeitsproblem Passat TDI 81 Kw | Posts 16+

First of all, thank you for your contributions.

I'm just wondering if the turbo whistle is between 1000 and...
1800 RPM is normal.
The whistling sound can be heard as soon as the engine speed increases.
The whistling sound is also proportional to the engine speed.
That means:
'For example, if you're at 2500 RPM and you depress the clutch...'
The engine speed has dropped to approximately 900 RPM, and you can hear a whistling sound.
expires.

Do you experience the same thing?
Or is there a report of damage to a charging station here?
Could it be due to the oil?
The previous owner always used 10W40 oil.
Currently, the engine has 5W30 oil in it.

Regards,
Hturbo01

Sure, here is the translation of the text from German to English:

'Addendum:'

I once experimentally increased the fuel injection amount.
And again, the engine went into emergency mode at approximately 210 km/h.
jumped.

After adjusting the boost pressure using a potentiometer (special electronics).
(increased to improve print quality).
The phenomenon has not reappeared.
(But I reassembled it again.)

My conclusion:
With an increasing fuel injection volume (without increasing boost pressure), the...
The relationship between the throttle position, boost pressure, and air mass is too high.
out of range
And once it reaches a certain size, the control electronics switch to emergency mode.

And with my worn-out nozzles, the phenomenon was even more pronounced.

Regards,
Hturbo01

hturborbo01 wrote:

My conclusion: With an increasing fuel injection volume (without increasing boost pressure), the... The relationship between the throttle position, boost pressure, and air mass is too high. out of range And from a certain size, the control electronics switch to emergency mode.

Hi.

I'm not sure I believe that, because I suspect you increased the boost pressure by manipulating the sensor readings.
However, the engine's computer essentially doesn't register any of this, meaning it's operating with the same input parameters as usual.
(The intake air temperature might have been slightly higher due to the increased pressure, but this could also be caused by a higher ambient temperature even with normal boost pressure.)

Therefore, I believe your observation was coincidental. Unless, of course, you increased the boost pressure by modifying the engine control unit (ECU) – also known as chip tuning.
Or the emergency mode might be triggered because the excessive boost pressure cannot be properly limited to the target value, but with the reduced sensor signal, the value that the engine computer "sees" is still within the acceptable range.

Hello Ulf,

Of course you're right, but keep that in mind when increasing the boost pressure.
The air mass is also increasing.
And these are, of course, registered by the mass airflow sensor (MAF) and sent to the control unit.
reported.

Sure, here's the translation:

'z.B.' translates to 'for example' in English.
If the boost pressure were increased by 0.2 bar from 1 bar, the air mass would also increase.
to account for this factor (approximately 20%).

Because: V1 x P1 = V2 x P2 (at constant temperature).



That's why I already believe that the phenomenon mentioned above...
which no longer occurs with the higher boost pressure.

Can you tell me something about the charger whistles?

Regards,
Hturbo.

Hi,

hturborbo01 wrote:

Can you tell me something about the charger whistles?

You are describing a phenomenon that anyone who has paid a little attention in physics should be able to explain themselves.
Sound waves are periodic compressions of air. What happens inside the turbocharger due to the rotating impeller blades? At the edges of the impeller blades, near the variable geometry (VTG) guide vanes, the air is periodically compressed (and not just there). Because this happens at a very high frequency, the emitted sound wave is also quite high (whistling). The sound of the whistling stops when the turbocharger stops, as you described. As the turbocharger speed increases, the frequency of the sound wave increases until it becomes so high that your ear can no longer perceive it.
I don't notice anything unusual about it.

The amount of soot buildup in the turbocharger varies, causing one turbocharger to whistle more and another to whistle less. VTG turbochargers are naturally a bit louder than wastegate turbochargers. Compare your turbocharger to other VTG TDIs - typically, all the VTG turbochargers in TDIs whistle.
Earlier, I already explained to you that leather squeaking is normal.

A faulty charger often makes a loud noise across the entire speed range. Sometimes it's so loud that it's impossible to have a conversation in the car.


P.S.: By the way, is it actually a habit of yours not to answer the questions that are asked to you?

Hi Bertil,

Of course, it's not a habit to avoid answering questions.
I thought the discussion with Ulf would answer your questions.

Of course, I will answer your questions, even if...
These are arriving a bit late.

Regarding the nozzles:
I haven't conducted a detailed technical test with the nozzles.
carried out.
Since I didn't experience the symptoms of a faulty needle lift sensor,
I assume that was okay.

Regarding the chip:
Certainly, this chip will improve this phenomenon.


Here's another question from me:
Habe testweise den Stecker vom Ladedrucksensor (incl. Temperature controller.
deducted.
The whistling sound was barely audible, even at higher speeds.

After that, I disconnected the vacuum hose from the turbocharger.
The whistle remained unchanged.
In the lower RPM range, I had very little power.
Around 3000 RPM, I started to regain power.
The engine went into emergency mode at approximately 3500-4000 RPM.
(Of course.)
Could it be the turbocharger pressure sensor (for VTG) or the boost pressure sensor?
are defective in the intake manifold.

How can I best test these myself?

Regards,
Hturbo01

Hi,

hturborbo01 wrote:

Regarding the nozzles: I haven't conducted a detailed technical test with the nozzles. carried out. Since I didn't experience the symptoms of a faulty needle lift sensor, I assume that was okay.

If the engine switches to limp mode at high RPM, that can be a possible symptom of a failing NOx sensor. Since the problem disappeared with a new set of injectors, it's likely that the NOx sensor was starting to fail.

Quote:

... Here's another question from me: Habe testweise den Stecker vom Ladedrucksensor (incl. Temperature controller. deducted. The whistling sound was barely audible, even at higher speeds.

Sure, because now the VTG (variable turbine geometry) will remain in a position where the most exhaust gases are directed towards the turbocharger turbine.
A certain amount of whistling is normal.
Compare it to other TDIs first.
Is it more or less?

Quote:

How can I best test these myself?

Test drive using VAG COM or a similar tool.

Hi,

I would definitely say it's a bit louder than the others.
You can clearly hear it between 1000 and 1800 RPM.

A charging damage might be imminent.
Could other defective parts be causing the loader pipe to fail?
be triggered.

Regards,
Hturbo01

Hi,

hturborbo01 wrote:

A charger damage might be imminent.

So far, the initial charger failures I've heard about have been more like a vacuum cleaner-like whining sound, rather than a whistling noise.

Quote:

Could other defective parts be causing the loader pipe to fail? be triggered.

If something is broken somewhere... I can imagine that happening. But it's probably not very common.