AVF motor flow noise up to approximately 2000 RPM

Hello everyone,

I've been a silent reader for quite some time, but today I also have something to say .
I've had a Passat 3BG, manufactured in 02/2004, with 80,000 km on the odometer, equipped with a TDI PD AVF engine (transmission: AG5, Tiptronic), and I'm very happy with it.
The car is running well, but I've noticed that between approximately 2000-2300 RPM, and with increasing load, there are strong air flow noises (I suspect they are coming from the pressure side, possibly near the turbocharger). Not too loud, but you can definitely hear it.
Today, I compared it to another AVF (Active Vibration Filter) in an A4, and there was nothing to hear.

It could be described as 'puffing' or strong 'slurping.' It's not the normal whistling sound you hear at partial load, it's something different. It also has a bit of a gritty texture.

Could this be related to leaks in the charge air system that the turbocharger is still able to compensate for?
VAG Com shows good pressure readings, up to almost 2500 mBar of absolute pressure .


And another question:
Is there anywhere a measurement block for oil temperature or oil pressure?

Thank you in advance.

corryfan wrote:

that up to approximately 2000-2300 RPM, strong air flow noises (likely on the pressure side, near the turbocharger) occur with increasing load. It could be rephrased using words like "blowing" or "loud slurping." Could this be related to leaks in the charge air system that the turbocharger can still compensate for?

Yes, that is quite possible.

I would like to investigate the issue (look for oil leaks, check the pipes, etc.) before the loader potentially suffers permanent damage due to constant overload.

What should one pay particular attention to when dealing with arteriovenous fistulas (AVFs), and are there any specific considerations?
I will write again as soon as there is any news.

Okay, I've been looking into the engine issue a bit (I've only driven carbureted engines so far). There was some oil in the intercooler hose, but it was just a thin film. It should be normal. All the hoses accessible from the top were okay.
Everything else is up to VW to check; let's see what they find.

Could it be that the AVF (presumably a vehicle or system) is no longer processing engine oil temperature data? There is also no value for it in the label file.
Same question about:

- LLK temperatures before/after LLK.
- Exhaust temperature sensor for turbocharger.


I can't find any values there. Is that really not available?

corryfan wrote:

There was oil in the charge air cooler hose, but it was only a thin film. It should be normal.

Yes, that's normal. What's concerning is the oil leak on the outside of the pipes/coolant lines -> see articles about common errors.

Quote:

Could it be that the AVF is no longer processing engine oil temperature data?? There is also no value for it in the label file. Same question about: - LLK temperatures before/after LLK. - Exhaust temperature turbo

I'm not familiar with oil temperature processing in the MSG. The AI system analyzes this data in conjunction with the WIV calculation.

For LLT (Longitudinal Transmission) after LLK (Longitudinal Load Compensation), there is a readable diagnostic value in the main control unit (MWB) 7. It approaches the outside temperature in long, gradual phases and reaches its maximum value within the Pmax range.
There are no temperature sensors (in standard production cars) before the LLK (Kühler) and before the turbine.

Okay, so, today I went to the and drove around the area with the master.

Result:
The noise from the airflow (which can be heard from LL up to approximately 2500 RPM) is 'normal' and tends to get louder with increasing mileage. What do you think about this? Could that actually be the case? Does anyone have any experience with this regarding AVF (Arbeitsvermittlungsförderung)?
My comparison vehicle had 50,000 kilometers less mileage (30,000 km instead of 80,000 km), perhaps that's related.

In addition, the hose under the LLK (likely referring to a specific component) is leaking (by the way, it's normal for them all to leak, and there's nothing you can do about it. I'm almost speechless).
Please provide the image so I can translate the text.

How can one (possibly) determine if the loader has been damaged by the leak over the last few kilometers, or if there is something wrong with the loader? As I mentioned, the car is running 'normally' well, so from a driving perspective, I would say everything is fine.

I still have 3 months of warranty on this new product, after which it will expire.
Sure, no problem!

[img][/img]http://www.car-revolution.de/passat/IMG_0334_2.JPG{MARKER}

'The 'good' guy is right! I don't know of any AVF (Automatic Valve Flange) that doesn't leak at this point! It's not necessarily a major issue. However, I didn't want to accept it because it was contaminating my foam blocks used for underbody protection. The friendly mechanic couldn't fix it with new seals, which is a common problem. So, I sealed it myself. I obtained new seals and installed them using a special sealant. The sealant is resistant to oil, temperature (up to 300°C), and pressure, and it doesn't stick. This is important for disassembly.' I've been using it for about half a year now, and the connection points of the liquid cooling system are completely dry!
However, despite that: this seepage seems to be quite normal. It's happening precisely in that area where the hot oil vapor condenses back into liquid as it cools, and then collects at the lowest point. And those connections probably weren't as tight as they should have been, but they should have been.

Greetings.

Hi,

Try to figure out if it's just a small amount of oil leaking from that spot, or if there's a significant amount of air escaping. The former is not critical, the latter is. I had a hole in almost exactly the same spot at the very beginning... and that was noticeable because of the noises I described. It was so loud that you could hear it even from inside the building.

Okay... remove the disguise, put your hand in front, and let someone give it full throttle. Even if it is claimed that you won't notice anything... in my case, a clearly noticeable jet of air came out.

Get it sealed and you're good to go (or do it yourself).

Due to my lack of knowledge at the time, excessive reliance on the dealership's advice, and despite the existence of online forums, I drove the brand new car for almost 5,000 kilometers like that (well, back then... early 2002). It hasn't caused any damage... with now 65,000 km on the odometer, the engine and turbo are still running perfectly.

Best regards,

Jan.

Sure, go ahead.

However, does the LLK accumulate oil sludge over time, or does it not?

Hi Mady, it's me .

Regarding. LLK:
No, I don't believe that, because the system only contains pure engine oil, and only in minimal amounts. At least, that was the case for me when I sealed it. There was absolutely no 'dirt' or mud.

Regards,
Mike.

Jan6K wrote:

So... take off the disguise, put your hand in front, and let someone give it full throttle. Even if it is claimed that you won't notice anything... in my case, a clearly noticeable air stream came out.

Hi Jan,

"Non-elastic" holes can be identified with certainty in this way.

Without assistance, you can use VAGCOM to access the basic settings of control module 11 and hope that the idle speed (which should be around 1400 rpm) is increased. At 100 mbar or higher pressure, with a leak detection rate of 10 seconds, it will whistle quite loudly from all the holes.
Does the idle speed remain at 900 rpm? If so, you're just as informed as you would be in normal operation.

Cracks, etc., that only open at a higher pressure cannot be detected in this way, but only by analyzing the oil or by pressing the lower link (LL) section.

Quote:

However, does the LLK accumulate oil sludge over time, or perhaps not

Sludge is not only composed of oil, but also contains a high proportion of debris and other particles. Where should those parts come from that are located behind the air filter?

Without assistance, you can use VAGCOM to access the basic settings of control module 11 and hope that the idle speed (which should be around 1400 rpm) is increased.




Hi,

I've already done quite a bit with VAGCOM, but somehow I'm stuck right now. Measurement blocks and basic settings?? Could you please explain it to me ?
On Friday, I'm going to the to replace the sealing ring. I will test beforehand to see if it was 'airtight.'

corryfan wrote:

I've already done quite a bit with VAGCOM, but somehow I'm just stuck right now. Measurement block and basic settings ??

If you don't know what a measurement data block means, what have you been doing with VAGCOM?
-> Dial 011 and select "Basic Settings".

See also /viewtopic.php?t=10810.

Regarding VAGCOM: It probably doesn't work in the shareware version, which is why I'm unfamiliar with it. I'll check it out when it's in full season.

Regarding the hose:
I received 2 new seals today (by the way, there are 2 part numbers, and one of them has been replaced). Probably an optimized part?))
Unfortunately, we didn't check the air tightness because we were under time pressure and the mechanic assisting us wasn't very cooperative (they tend to be dismissive, saying things like 'they're all leaky anyway').

My engine noise is still present, and it's clearly coming from the area around the turbocharger, which is located in the front on the right side.
It seems like the engine is running better now; I'll test it thoroughly tomorrow (with two trips of 450 km each).

Hello!

Until yesterday, I also thought that the noise was normal. I have that too.
I slid it onto the hose connector, which is arranged slightly differently on my A6 but looks the same.

When I bought my car (A6 1.9 AVF), I immediately replaced the leaky connections with new ones.
now fitted with green sealing rings (the old ones were black and crushed due to incorrect installation).

Yesterday, while working on my car for a different reason, I noticed that the hose connections at the bottom were smeared with oil again.

I think I've found the cause. My connection is currently down for a distance of 200 km.
The clamp that secures the pipe engages behind two protrusions on the connecting pipe.

My guess is that the nozzles are wearing down due to abrasion caused by vibrations.
So that the hose can be pushed slightly out of the coupling using the boost pressure.
(unless it was designed that way from the beginning / I have no idea, I bought the car like this).
Upon closer inspection, the insertion tube is centered within the socket of the mating part by small protrusions located at the end of the cylindrical section of the insertion tube. When pushed outwards, these protrusions rest on the edge of the socket and gradually engage. Eventually, the wood can split or the grain can become so compressed that the insert sleeve is no longer centered.
Bending moments (from the rest of the pipe) and self-weight forces are now acting on the seal. Due to this pressure, the gasket flattens at one point, creating a free cross-section on the opposite side of the pipe.

=> leaky connection.

I used TIG welding to add some material behind the locating pins and then used a file to create a new contour.

My connection is now stable, but that wasn't the cause of the problem.
The sound was coming from my engine. In my case, the pressure hose between the turbocharger and the intercooler's connection point on the side had split. He unfortunately sprayed the oil into the fender in such a way that it was impossible to see from above, and could only be seen from below with a flashlight.

Best regards.

wvg

hi
Thanks for the great contribution. I'll double-check everything and let you know.
By the way, I also had the black seals installed (my car was manufactured in February 2004), and now there are two green seals installed.

The vehicle is running just as well as before, there seems to be no difference.

'@ulf: It is possible to increase the RPM setting even with the 'default' configuration!' What exactly is happening there?

'It doesn't quite fit the topic, but does anyone know what 'status 2, 4, or 6' means for PD elements?' On Saturday, I logged approximately 300 KB of data (during two highway trips of 450 km each), and this issue occurred occasionally.

Sure, here's the translation:

'Hello' or 'Greetings'
Sebastian.