Turbo noise

"For some time now, I've been experiencing a second turbo whistle. It's a light, high-pitched whistling sound that's noticeable at idle, but disappears completely under higher engine load. The normal turbo whistle is still audible when there's boost, and it sounds quite different." It is clear that this noise is coming from the charging system, as the pitch changes depending on the accelerator pedal position.

One possibility would be a leak, but I can't find anything. He drives normally, the error memory is also clear, and no changes in soot emissions are detectable.

Another possibility would be damage to the turbocharger's bearing, as the whistling sound disappears when the turbo is under load.

Engine: AHF, with VTG turbocharger, slightly increased boost pressure due to chip tuning. 180,000 km, otherwise no major issues.

"Who recognizes this sound? How does bearing damage manifest itself?" How can I test the turbo?

Best regards,
Uwe

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Another possibility would be damage to the turbocharger's bearing, as the whistling sound disappears when the turbo is under load.

'Who recognizes this sound? How does bearing damage manifest itself?' How can I test the turbo?

Best regards, Uwe

Hi Uwe,

To start the test, I would begin by disconnecting the vacuum hose from the VTG control unit. If the whistling sound is coming from the charger, it should be noticeably quieter.
Next, I would check the serpentine belt, as it can also cause squealing noises, especially if it has been overtightened.

I looked again. It's definitely a mechanical noise coming from the turbo, not a blow-off valve or anything like that.

"Of course, there's not much you can do besides hope it lasts. Has anyone had experience with noisy turbochargers? What's the cost of a new or replacement one?" Is it possible to repair it?

Best regards,
Uwe

Hi Uwe,

If it's indeed the turbocharger shaft that's slowly failing, it's possible that you might end up with a significant amount of oil in the intake air path over time. It's a good idea to check it periodically to prevent the TDI engine from running away.

Hi,

The whistling sound has been discussed here before - mine has been whistling for a long time - and I think it sounds good. I don't think that means he's going to resign.

Damage to the storage area would not cause whistling sounds. As soon as it has any real gameplay, the whole thing falls apart.


For me, it's likely tolerances between the gas turbine and the housing, possibly also between the housing and the compressor wheel, or deposits.

Don't worry - as long as there's no significant oil leakage, everything is fine.

Okay, a squeaking noise also bothers me. It can be caused by a faulty bearing. I believe that it will likely take a relatively short time before you start experiencing real problems.

I used to drive my old AAZ with the first turbocharger, running at more than double the boost pressure. Then I learned. Between the point where it started making strange noises and a complete failure, I only managed to drive about 70 kilometers. However, I don't know how long the aging process takes when you don't push the boost pressure too much.
It was interesting that the pipe was dirty. It wasn't a pure, high-pitched 'sssssss' sound, but rather one with a slight fluttering undertone.

Now we know why it's whistling. Since today, it's been making a terrible noise and no longer producing any boost pressure. In other words: He is gone .

What is the cost of a turbocharger, and where can I find one at a reasonable price?

VTG Turbo, AHF.

Best regards,
Uwe

"While driving on the road, the power decreased under full load. I then took my foot off the accelerator and noticed a louder charging sound. The engine was still running smoothly. I continued driving with minimal power. The whining sound was constantly changing, and the turbocharger barely reached its operating speed (sound). I don't have any LDA (Linear Drive Assist)." It's quite clear from the sound that the loader simply isn't revving up enough.

"There are no vibrations, so the loader buckets seem to be fine. I suspect the bearing is stiff. There are no leaks, the oil level is still okay, and there's no smoke either." It only produces sounds, not pressure.

I won't be able to look at the car until next week, as my weekend is already fully booked. However, I don't really know of any reliable ways to get an exact diagnosis. However, in my opinion, the case is clear, and the device is beyond repair.

I will probably exchange it next week .

Does anyone have any tips?

Best regards,
Uwe

"That crappy turbocharger isn't exactly the end of the world." You can find those things used for as little as 90 euros.

Okay, I've finally gotten around to removing the loader. The bucket attachments are completely gone! They've disintegrated or been sheared off. That's all there is to say about the noise of chargers!

The intake manifold is clean, so all the shavings have passed through my engine! Grrrr...

The new charger has been ordered. I will install it tomorrow. How does an engine handle it when it's fed this difficult-to-digest fuel?

Best regards,
Uwe

Uwe wrote:

Well, now I finally (had no time) to remove the loader. The bucket scoops are completely gone!!! They've dissolved or been sheared off. That's all there is to say about the noise of chargers! The intake manifold is clean, so all the shavings have passed through my engine! Grrrr...

Hm, do you happen to know roughly what "granularity" the shovels were broken down into? And what obstacle did they come into contact with?
Are there absolutely no debris to be found in the LLK (presumably referring to a specific location)?

The charger finally broke down completely at full load on the highway. It wasn't a sudden failure, but a gradual one. I noticed that the maximum speed was decreasing. When I realized that the engine wasn't running properly (about 3 kilometers), I slowed down very, very slowly. It was already too late.

Based on how the loader looks, it seems like the bucket teeth were slowly breaking apart. I suspect that only small pieces broke off, otherwise there would likely be something else stuck in the intake tract. That wasn't the case, it was all just hot air.

I drove about another 100 kilometers by car, but without putting any strain on it. Therefore, I cannot yet make any statements about possible damage. I will know more tomorrow.

Best regards, Uwe

Hello,

'I've also had the whistling noise from the turbocharger for about 20,000 km. It worried me a lot at first, but now it doesn't bother me much. The boost pressure and turbocharger response are perfectly fine, but now that I'm hearing about your turbocharger failure, I'm a bit worried again. The turbocharger shaft play was also fine, and the shaft wasn't stiff.' I hope I don't have the same experience as you do, my apologies ..


Sure, here's the translation:

'Best regards, Dr. B.'

We really should create a sound database sometime.

It's really hard to put into words...

'This trucker's MAN truck has had a distinctive 'whistle' sound for 15 years. I can immediately distinguish it from any other truck.'

What constitutes a 'good whistle' versus a 'bad whistle' cannot be described with words... it's a frustrating thing.

'Some people who drive cars with wastegates say my ALH sounds completely broken... but all the VTG-TDI engines I know sound the same, because that's just normal for them.'

I'd like to record it, but I'm lacking the necessary hardware.

CU Gremlin.

Well, unfortunately, it's too late for me. I can't record any more whistles...

Best regards,
Uwe

'Some people who drive cars with wastegates say my ALH sounds completely broken... but all the VTG-TDI engines I know sound the same, because that's just normal for them.'


There's still a difference, even with VTGs. Unfortunately, our ATJ can't produce that characteristic 'whine' sound, even though it has a VTG turbocharger. The ATJ turbocharger in our car reminds me more of our wastegate turbocharger from our old 1Z, except that it can also make a slight hissing sound when running at normal operating temperatures.

Best regards, WarLord.