Loader won't start? Troubleshooting guide.

...and I have no idea why.

Yesterday evening, I parked the car as usual, and this morning when I went out to get some bread, I noticed that the engine was making a loud noise. The noise almost disappears as the engine warms up. It's most noticeable at engine speeds below 2000 RPM and under a slight load.
I'm naturally a bit worried that my battery might fail around 124,000 km.
I already checked to see if there might be a leaky hose, but I didn't find anything. Also, the car is no longer producing any black smoke.
It's about an automatic fuel nozzle in a 1998 Passat.
Does anyone know anything about this?

best regards
Ronny.

Hi,

'I don't know why he's doing that either, but my car behaves the same way for the first few meters when it's cold. I especially notice it in the underground parking garage. It's now done 140,000 km with that issue.'

Hello,

'Hmm, I'm just surprised that it appeared so suddenly. And it's already so loud that it's immediately noticeable. The car also doesn't seem to have any loss of power...'

best regards
Ronny.

Hello, fellow diesel enthusiasts.

Could the noise be coming from a belt tensioner?
I had something similar on my Astra years ago.

Best regards, Chrigu.

Hello,

I'm experiencing the same 'problem.' No one here has been able to explain the cause. You can clearly hear the turbine noise. Of course, the turbocharger *is* a turbine, but why did I never hear it before, and why has it only started happening from yesterday to today?

Regards,
I'm sorry, I don't understand. Can you please rephrase your request?

Hello Wollif,

Hmm, so, exactly the same thing with you. How long have you had this problem? I mean, it's clearly the speed of the turbocharger that you're hearing. But why is it happening so suddenly?

best regards
Ronny.

rl2664 wrote:

I also think it's clearly the speed of the turbocharger that you're hearing. But why so suddenly?

Hi everyone,

Sure, here's the translation:

"Just a small tip:"

Loudspeaker noises change their pitch noticeably, but always somewhat delayed compared to the pedal movements, even if the engine speed doesn't practically change at that moment.

If the pitch is directly related to the motor speed, then it is fundamentally something else.

@Ulf:


Loader noises change their pitch noticeably, but always somewhat delayed compared to the accelerator pedal movements, even if the engine speed doesn't practically change at that moment.


Yep, that's exactly it. I think I can tell the difference, and it's definitely the charger. I can already see myself getting a new one.

Hi Ronny,

The noise appeared around 200,000 km. The car has now reached 230,000 km. It definitely comes from the turbocharger. I hope it lasts a little longer... This is a Golf III, manufactured in December 1994.

Regards,
Frank.

Depending on the imbalance of the rotating component, different noises are produced. The imbalance can also change over time.
The impeller is screwed onto the shaft and also held in place by a tight fit. At high impeller speeds, it can happen that the tight fit is temporarily insufficient (due to centrifugal forces), causing the impeller to rotate slightly on the shaft relative to its initial position. This changes the imbalance, which in turn alters the bearing load and noise levels in certain impeller speed ranges.

Thomas.

Here's some information about the topic:

http://www.motair.de/

Thank you, that sounds plausible!

@ Thomas:

That sounds quite interesting. I think I understand it, but I'm not sure what to make of it yet.
Is this noise normal, or will this 'twisting on the shaft' cause bigger problems in the long run?
Unfortunately, I don't really know much about turbochargers.
My friend (who works on VAG cars) also listened to it and said it's probably just a normal turbocharger sound.
One thing is certain: Motair is in Cologne, and not far from me. If the charger breaks down, they should investigate what caused it. Perhaps the repair will be cheaper than replacing it with a new part.

best regards
Ronny.

The rotor assembly is balanced to minimize noise emissions (riding comfort) and reduce bearing loads. The imbalance depends on the rotor speed and acceleration. Many people are familiar with this from poorly balanced wheels or brake discs – the imbalance is only noticeable in certain driving conditions. I cannot assess whether the imbalance in your case is still within the tolerance limits, as it depends on the specific rotor and vehicle (noise comfort). However, if your mechanic considers the noise to be normal, I would not change anything.
I'm not familiar with the specific "Motair" you're referring to, but during a maintenance procedure, the bearings and other small parts are replaced, and the main body is rebalanced. If the noises become louder or new noises appear, the loader can still be overhauled.

@Thomas:

Thank you for the information. I will keep an eye on it.

best regards
Ronny.