Does my turbo have a problem?

Hello, I'm new here. Therefore, first of all, a big hello to everyone!

I have a G3, model year 1994, with a 1Z engine.

Two days ago, I noticed a whistling sound. It's coming from the turbo! He's never made that sound before. It starts around 1500 RPM. When I let off the gas, it's still audible for about 2 seconds before it disappears. It's also strange that it's not always audible with every acceleration. I've checked the pressure lines. Is it okay to leave it like this? I haven't noticed any loss of power. I would appreciate responses.

Don't worry, everything is okay. You just haven't noticed the whistling before. If you don't hear it sometimes, it's probably due to other external conditions, or maybe someone installed a diesel engine overnight.

It just makes me curious that I haven't heard it in 3 years. That whistling is actually quite piercing! If it's something serious, I'm sure I'll notice it soon.

So, I've only ever heard it when I'm driving along near the wall. Otherwise, virtually nothing reached the interior.
After increasing the boost pressure to 0.9 bar, the shaft developed play after 70 km. This became immediately noticeable. I was on the highway at 160 km/h and talking on the phone when even the person on the other end of the line could hear the turbocharger. I immediately pulled over and couldn't see anything externally. While continuing on, I noticed that the charger wasn't providing enough pressure.
My loader didn't always whistle. It was silent when running at full load. The pressure was gone.
A service was due.
I sent the turbocharger to STK-Turbotechnik (www.turbocharger.de). For approximately €370, it was re-sealed, re-bushed, and balanced. After 3 working days, the turbocharger was back. This is a turbo service. I completely forgot: they also painted it. So, it looks good again . However, I have the impression that they removed it by unscrewing the wastegate, which was sealed. I can't prove it, because my air intake (intercooler) is no longer original. But that's not a problem. The turbocharger is regaining its boost pressure.
Alternatively, the company Motair (www.motair.de - more expensive than STK) might also be able to help you.
But first, I would like to check the following:
- Is the turbocharger still building boost?
- Is there any oil leakage?
Regarding 'neither nor,' I would proceed with caution. However, in my opinion, it's not a good sign. How many kilometers does it have? A build year of 1994 is already quite old. Tuning?

Here's a post I wrote a few weeks ago:

/viewtopic.php?p=1590&highlight=#1590

Thanks for the tips. I'll try adding an LDA. I'll get back to you later.

It has now reached approximately 100,000 kilometers.

There is no oil leak. It's actually not really tuned. Except for a DAIT, which I happened to have. When reading the error memory, nothing was detected. I was told that this extreme whistling might be 'normal' for some models! We'll see how that turns out soon. And I haven't installed the LDA yet, but I'll be putting it on soon. Then you can see further.

I finally managed to install the LDA. I also added an oil temperature sensor at the same time. So: The LDA shows me 0.5 bar of boost pressure during acceleration at 2000 RPM. The maximum is 0.9 bar at approximately 3200 RPM. Is that within the 'normal' range? Or is the turbocharger spooling up too late? Should the turbo not be regulated to 1 bar?

Best regards,

I don't know how it works with the 1Z, but from my perspective, it's too late.

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Here's what it looks like with the ASV; the maximum pressure is reached at just under 2000, and I think yours should be only slightly higher, not significantly later. A maximum of 0.9 is, in my opinion, correct for the 1Z.

Don't be misled by the values in the diagram; the control unit measures absolute pressure, so 1 bar corresponds to 2000 mbar absolute pressure.

Best regards,

Jan.http://www.informatik.hu-berlin.de/~richling/tmp/2b2.png{MARKER}

I forgot something important. I only get it to 0.9 bar if I briefly go to full load between 3000 and 4000 RPM. Earlier, I tried something else. Going slightly uphill in 4th gear, from 2000 to 4000 RPM, I get a maximum of 0.7 bar. Is that normal? Does anyone here drive a 1Z that I can compare values with? By the way, the whistling sound is unchanged. And it still runs for a long time after being turned off. But the workshop, of course, says that everything is OK, everything is normal! But I'm not entirely sure about that. I don't have the resources or the time to remove the turbocharger. And expanding and having it inspected costs money!

Best regards,

Hello,

I drive a 1Z. Volkswagen Golf 3, manufactured in 1995.

Coincidentally, I also installed a boost gauge this past weekend. Just out of curiosity.

Since I believe everything is running optimally with my 1Z, we could compare them.
However, I haven't driven the LDA much yet.

The pressure builds up to approximately 0.5 bar from around 1,500 rpm. It's more likely to be related to SDI (Strategic Defense Initiative).
At approximately 2,000 rpm, I reached the 'full boost' of 0.9 bar.
And when you suddenly accelerate at higher engine speeds (from around 3,000 rpm, for example, in 5th gear). (During highway driving), there is even a brief spike up to 1.1 bar.
However, they are then immediately regulated to approximately 0.9 bar.

That suggests that something isn't quite working optimally for you.
As I said, I still need to test things out a bit more on my own.

Markus.

Sorry, it's me again.

Of course, for a comparison to be valid, your boost pressure gauge must be working correctly.
I certainly don't want to question your crafting skills (I don't have any noteworthy myself).
But it would be important to know where you connected the LDA hose, etc.
Perhaps she is showing less interest than she actually feels.

P.S.:
Who initially experienced significant problems with a trembling pointer in an analog LDA (Laser Doppler Anemometer), even to the point where it produced a noticeable vibration?
I fixed it by inserting a piece of foam into the tube, which dampens the resonances and pulsations to such an extent that the LDA still displays accurate readings, but no longer vibrates. I don't observe any significant delay in the display.

MARKUS.

I cut the pressure hose about 30 cm in front of the control unit, installed a Y-connector, and secured it. How did you fix your hoses to the connector? There's always something to learn. I would be very happy if it were a leak in the hoses. But since I installed the LDA, for example, nothing has changed in terms of performance (purely subjectively). I always drive a longer uphill section on my way to work, where I always test. Shouldn't I also observe differences in performance if some of the pressure is lost?

Best regards,

Hi.

. . . whether you might have connected the "wrong" hose to the LDA.
For example, in the 1Z engine, tapping into the hose between the charge air cooler and the solenoid valve would result in an apparently too low boost pressure.

"However, the hose from the intake manifold to the engine computer is the correct one for the LDA, and based on the pressure values you described, your car likely doesn't pull as well as a healthy 1Z engine in the mid-RPM range."

When there are problems with boost pressure, the magnetic valve responsible for boost pressure regulation is often the culprit.
Just try switching it out for a moment; maybe you'll feel "real pressure" again.

Hi, TDI-1Z!

I also tapped into the boost pressure line for my LDA using a Y-connector on the hose leading to the engine control unit.
As Ulf already posted, that's definitely okay.

Regarding your question about how to securely attach to this Y-shaped piece:
So far, I haven't added any additional fastening there...
The hoses are also very tight on the Y-connector for me.
Nothing will slip. Also, I quickly checked at the hardware store, but I couldn't find a hose clamp that small.
So: If the hoses are stuck, it won't affect the engine's performance.
And if, for example, your LDA (Leak Detection Apparatus) in the interior was leaking (e.g., at the connection), you would hear a distinct hissing sound – something that actually happened to me once when the hose came loose...

Therefore, the values we have posted are likely comparable.
That suggests again that something might not be right with you.
You might have a leak in the pressure system (the section from the charger to the battery management system and from there to the motor).
The 'loud whistling' you're referring to could also be an indication of a leak in the cooling system. I have often heard that, especially in the case of leaky LLK (likely referring to a type of hydraulic fluid), there is a tendency for it to make a hissing or whistling sound.
(Correct me!)
Those would be the cheapest solutions to try initially.

MARKUS.

Since we're talking about LDA, a quick note from me: Where can I get an LDA at the best price? While I have the option to monitor the pressure using VAG-COM, I'm not entirely comfortable with it.

VAG-COM values are very accurate, as they are the values that the engine control unit also uses for its calculations. The only disadvantage of this method is that you won't be notified if the sensor fails; you would only see that on an LDA (likely referring to a diagnostic display).

To find it: Check Conrad's website under "automotive accessories."

Due to hissing from a leaking expansion tank: I can confirm, mine did the same thing when it was leaking. At around 2000 revolutions per minute, when accelerating, there was always a noticeable hissing sound.

After the repair, it was completely gone.

Best regards,

Jan, who also plans to install an LDA (Linear Discriminant Analysis) at some point.