TDI Whining Noise: Causes & Solutions

After driving my car for 70000km (with quite a few problems, actually), and having taken it to the workshop regularly for several weeks due to a rattling/whirring noise (especially noticeable at idle), I receive new bad news every day! I believe the noise has been there since the beginning, although not as loud. But: a few weeks ago, when I took the car to the workshop because of the noise, they said it was the water pump and/or the timing belt. After replacing all of that, everything was the same; it still rattles/whirs! Then, they thought it might be a vibration damper on the crankshaft! They replaced that last week, and the result was: that wasn't it either! Yesterday, they told me it could possibly be the 'collector' (what is the correct German word for that? ). Today, while working on the turbo, they also noticed that it's somehow leaking oil!!! Now I'm also getting a new turbo, but not until Monday because the part needs to be ordered! So, I don't know, but I'm thoroughly fed up! I just want to drive my car without any rattling/squeaking noises, but that apparently isn't possible. I'm disappointed with my car, and as a student, you can't just buy a new one. But what could be the reason why the turbo is leaking oil? Is there too much oil in it (or was there too much), is the turbo really already at the end of its life??? I drive the car VERY gently, always warm it up carefully, usually let the engine run for a few revolutions before turning it off, always check the oil, etc.! So, what else can I do to make everything last? 70000km, that's not the world!

So, if you drive the TDI as described below, there's no surprise.

I've driven several 3-cylinder engines, and only the one with 90 horsepower impressed me with its performance.

You can throw everything about running culture straight into the trash.
The idle is just very rough; maybe you have to accept it.

Or invest in something else!
People who buy a car like that are actually just trying to save money on fuel, and somewhere along the line, there are always compromises.

If I were to buy a PD engine, I would only consider one with 115 or 130 horsepower.
"But the one with 115 horsepower already feels a bit too restricted at the top end!"

Hi,

Do you have to pay for the new turbo yourself, or is it covered under warranty/goodwill?

If that's the case, I would suggest getting someone else to take a look, because a little bit of oil leakage from the bearing seals is normal.

Was that noise really annoying, or just a little distracting? If it's the latter, then you probably have to accept it as "normal" or do something about it yourself. My Ibi also makes some rattling noises, but that's basically only coming from the instrument holder, and it can probably be fixed with a little tinkering (if I ever find the time).

Best regards,

Jan.

Regarding the first response: For daily commutes of 150km, I'm not necessarily looking for high performance or a refined driving experience, but rather reliability and fuel efficiency! The 1.4 TDI is economical and powerful enough.

Regarding the noise: it was and still is annoying. When the engine is really warm after 130km, you can clearly hear the scraping/rattling/whirring (which is also uneven and irregular) inside the car when it's idling. Since other Polos with this engine don't make this noise (neither did my first one), I assume it's not normal.
Furthermore, my car is only 1 year and 9 months old, so the turbo and everything else is still under warranty!

Hi,

If that's the case, I would insist on a thorough rework, especially if you know that other cars with the same machine don't have the same issue (because that undermines the argument that "it has to be this way").

However, I still don't believe that replacing the turbo will solve the problem...

Are you sure the noise is coming from the engine compartment and not from the instrument panel?

Best regards,

Jan.

I don't think a new turbocharger will solve the problem, but they saw that mine is somehow leaking oil, so now they're replacing it.
The noise is clearly coming from the right corner of the engine compartment (as viewed from the driver's seat), and also from the right wheel well.
'You could even tell me that the noise is okay, but I just don't want something to break after the warranty expires at the end of February!'
'I believe that turbochargers and noise are 2 different things. There's a noise that's constantly present and isn't normal, and on the other hand, the turbocharger has already reached 70,000 km with careful driving. What could be the cause of the oil loss? Does anyone know? Perhaps there was too much oil in the engine, or is too much oil 'not' harmful to the turbocharger? Furthermore, I doubt I've added too much oil in between.'

Okay, there's a campaign where the fuel feed line in the engine is being replaced (modified).
Since the pipe can pick up vibrations and transmit them to the body.

The impulses originate from the pump nozzle elements and then propagate.

I'm not sure if that description applies to you.

I had performed the procedure on an Audi A2. The customer did not complain about anything afterward. The new line has two round side chambers where these vibrations are supposed to be absorbed .

Having driven approximately 190,000 km with the AMF, I, as a technically interested amateur, have come to know a few of its quirks.
"Nevertheless, for me, it is by far the most elastic and economical engine in this power class. There is simply no comparable competitor. The only comparable option is the four-cylinder engine from Toyota, but it cannot compete with the AMF or the 90-horsepower version in any of the mentioned areas."
Furthermore, the engine is quite tolerant when it comes to chipping. This means that even without a Variable Turbine Geometry (VTG) system, the turbo lag can be practically eliminated by accepting a bit of smoke under full load in that engine speed range. Unlike common-rail engines, it is also compatible with PÖL (Pre-emission standards) regulations.
To be honest, I don't really care about the engine noise, so I'm not an expert on that. If I want sound, I'll drive an American V8 muscle car... or, alternatively, a Japanese high-performance motorcycle. If you want a quiet idle, you'll find it in the BMW inline-six engines.
Tractors are tractors, after all (especially those with PD engines). That being said, PD engines also offer significant advantages in terms of power and fuel consumption.

Subject:
The "chirping" sound is coming from the fuel filter. It seems that newer models have probably resolved this issue. However, a new diesel filter should provide some relief even for older models. A little dirt in the filter, especially in cold weather, can quickly cause the noise to return. Alternatively, you could turn up the radio or install marbles in the dashboard (which will be annoying, especially in turns).
To make sure it's the exact problem I described (but given the localization "front right," I'm quite certain):
Just try filling up with biodiesel or rapeseed oil. If the noise gets louder, it's likely the problem described.
Be careful: if biodiesel has never been used before, the diesel filter may become clogged and need to be replaced.

I hope I was able to help.

Olaf.

P.S.
I'm not sure what "defensive driving" means. But if you let the engine run for a few minutes after a cold start and then occasionally give it some gas, it's not harmful. Otherwise, the car will never warm up in the winter and will constantly run with completely cold oil. I've noticed more strange noises coming from engines that aren't driven properly. You can also exploit the power of an engine without ruining the clutch and transmission. The running quality of my car is also getting worse if I don't demand any power for weeks.
Regarding oil and turbochargers:
It's normal for a small amount of oil to seep out onto the exhaust side through the shaft. That's probably why the EGR valve is defective. The combination of soot and oil creates a great sludge.
Eventually, so much oil will accumulate on the intake side that not all of it can pass through the engine, causing the mass airflow sensor to become saturated with oil and trigger an error. The engine will then go into limp mode. At that point, everything should be cleaned, and the turbocharger should be repaired (new bearings, balanced). If you continue driving for a long time, there is a risk that the turbocharger shaft will develop so much play that the impeller blades will hit the housing, scattering metal debris everywhere. Furthermore, the oil consumption will suddenly increase dramatically, potentially leading to the engine running dry (all the engine oil suddenly flows into the intake manifold).
So, you would only claim the issue and have the charger replaced shortly before the warranty expires. The sooner you do it, the more kilometers you're essentially giving up that you could have driven with the old charger.
When that time comes likely depends largely on the number of cold starts. It's also not good to immediately turn off the engine when the turbocharger is very hot (a typical situation when you quickly stop at a gas station after a fast highway drive). This can cause oil sludge to form in the oil supply line to the turbocharger. If the turbocharger then doesn't get enough oil, the bearings will wear out more quickly. Increasing the boost pressure (through a chip) naturally increases this effect. A boost pressure control system that overshoots (causing pulsating acceleration) also has a negative effect. In this case, the turbocharger experiences very high pressures for short periods, which puts it under extreme stress.
Under reasonably normal circumstances, a loader should be able to last at least 100,000 km even with a chip. However, due to the lack of VTG (Variable Valve Timing Geometry), there are no issues in that regard with the AMF (presumably referring to a specific engine or component).
I can't say for sure what is most likely to cause the loader to fail, as loaders with this type of engine don't usually break down (unless the wrong oil is used).

P.S.2
"Steffarn's" explanation sounds quite plausible. It would also explain why the noise changes depending on the type of fuel (due to different density/viscosity).

Could it really be the diesel filter?
Okay, so regarding the noise: it's a regularly irregular whirring/rattling sound, like 'schschschsch...schschschsch...schschsch,' which is particularly noticeable from the outside when the engine is idling. However, it's also audible when I slightly increase the idle speed.
Regarding the turbocharger: the mechanic said that it was likely leaking a small amount of oil around the shaft.

I think I'll tell them about the idea regarding the diesel filter and fuel lines the day after tomorrow, and then we'll see how it goes.

Regarding the turbocharger:
My statements specifically referred to the oil being pushed by the wave.

Regarding the noise:
What I mean is a very high-pitched (!!! which is why many older people probably won't hear it) whistling sound, coming from the front right side of the car, and especially noticeable when idling. I don't know if it can be heard from the outside (I've never really been interested in that). However, it seems very likely that it's the same noise that Steffarn mentioned with the A2. The noise I'm observing is definitely related to the fuel lines. Just try this test and fill up with biodiesel. If it gets louder, then we're talking about the same noise.

Regards,

Olaf.

I would like to use biodiesel, but as far as I know, there is no biodiesel available for purchase in Luxembourg.
My noise level is not very high, however...

You can also try using PÖL (a type of fuel additive) from Aldi or Lidl for testing. However, please don't use more than 15% in cold weather (below 5 degrees Celsius), especially if you frequently start the engine when it's cold, as this can put a lot of strain on the timing belt and PD (common rail) injectors. Otherwise, if the tank is empty, you can add some and test it, and before a long period of inactivity, simply refill it with diesel overnight.

But it seems like it's actually a different sound... "chirping" describes it quite well.

Regards,

Olaf.

What should I be aware of when installing a new turbocharger? Do I need to 'break it in,' or does it not require any special attention?

I have my car back now, with a new turbocharger, but the noise is still there! They are now contacting the factory to see if they can find a solution.

I just checked it again, and they told me that my old turbo wasn't showing any play in the shaft, unlike the new one! So, in my opinion, the old one was probably still perfectly fine. Also, my car used 450ml of oil for 20,000 km.
However, we haven't made any progress with the noise yet!
But my car drives great, just like always!
I read somewhere else that they might be parts from a Lima truck, what do you think?

As I mentioned before... a little bit of oil seeping through is normal. If the engine isn't being used much, it unfortunately accumulates on the side exposed to the open air. The only solution is to give it FULL THROTTLE!!!!!!!
450 ml is quite a lot... but not really too much... actually, it's perfectly within the acceptable range.

Regarding the bra:
Then the noise probably isn't coming from the front passenger side...

Regards,

Olaf.