Vintage mechanics, solid

Hello!

To avoid writing excessively:
I bought a Golf IV a few days ago. It has 200,000 km on the odometer and was manufactured in late 1997. ALH engine.
The VTG turbocharger linkage is extremely solid, and the engine probably only has about 30 horsepower left, and it only revs up to around 2000 RPM.
This happened when I really "kicked" him for the first time. Previously, it ran normally, but it was only city traffic.
I assume that the mechanism somehow got stuck in the "up" position.
I read through the forum archives.

The car is currently on a lift, and I've removed the membrane from the turbocharger housing.
The control rod is located at the very top, and can only be moved about 2mm with your hand.
Even with a lot of force, it won't budge, and even though the engine is running, it's not working.
The membrane dose is okay; it pulls the rod down 2 mm, but it seems like it won't go any further.

Okay, I need a suggestion on how to proceed.
Can a relatively skilled mechanic repair the turbocharger and get it working again? (I can't possibly make it any worse).
or, better yet, install a different one or an AT charger.
That wouldn't be a problem, because I got the car for a very good price.

Hi Steffen,

Check this out:



Disassemble the turbocharger, verschandeln the hot side (possibly soaking it in diesel or brake cleaner), then...
should it work out again.

You can check the wave pattern beforehand to see how it performs, before you invest in the whole...
You're working with cleaning. More information here:

/viewtopic.php?t=6456&highlight=wellenspiel


Regards...

...Kuhni!http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html{MARKER}

Cleaning is almost free and can be done quickly. I've posted a guide/report here. Be careful with the manifold bolts, as they tend to break easily. Then, remove the turbocharger with the manifold from the exhaust system and unscrew the housing on the exhaust side. With some rust remover and a little coaxing, it should come apart. Behind it is the VTG adjustment mechanism. Maybe take a picture beforehand. Remove the three Torx screws and you'll have all the individual parts in front of you. verschandeln everything thoroughly. Usually, one or two of the vanes are completely stuck. Place the disc in diesel overnight and try to move it with minimal force the next day. It will probably work out eventually, and it's definitely worth a try.

And always remember:

Never loosen the bucket wheels from the shaft

m;

Of course, completely forgotten. There is absolutely no reason for that .

Since everyone is talking about cleaning, here's a small note from my side. The soot that inevitably deposits on the VTG (Variable Turbine Geometry) adjustment mechanism in a diesel engine has lubricating properties. In gasoline engines, these surge volumes do not exist. This, along with the higher temperatures, is a reason why variable turbine geometry (VTG) has not yet been implemented in any gasoline engine.

In many cases, it certainly helps to disassemble and reassemble the VTG (vehicle traction generator). However, it is rather unlikely that the problem will be permanently resolved, as it is often impossible to locate the exact spot where the part is jammed due to the number of components involved.

Hi vanilla.

Do you have any sources that you can use to substantiate the claim of "smearing"?

Thank you.
m;

Unfortunately, I can't provide any evidence for that, and I don't have the source information readily available. That's just a piece of wisdom.

Regarding the emissions of a diesel engine, particularly the composition of soot, I'm afraid I'm not very knowledgeable either. I'm just putting forward the hypothesis that there is a larger amount of carbon present in the soil.

Since my knowledge of tribology is not particularly extensive, I cannot provide you with a more detailed explanation of the lubrication properties of carbon/graphite. I think I once heard that it has something to do with the lattice structure.

What I'm sure of is that there are grease products based on graphite, or even graphite powder, available for lubrication.

Hello!

I thank you all for the quick and competent help!

Hi vanilla

Do you have any sources that you can use to substantiate the claim of 'smearing'?

Thank you.
m;

Hello Martin,

I've often heard from our diesel specialists that the black smoke produced by a diesel engine isn't a problem, but rather can even be beneficial. The pressure relief valves of the Turbo, etc., should be lubricated as described above.

The issue with Russian gas is, on its own, solely an environmental problem, provided that exhaust temperatures remain within acceptable limits.

Best regards, Jochen.

I'm actually interested in whether the Russian is "quite nice" because he's a bit of a smooth talker.

or

whether it is absolutely necessary.


For me, so far, the exhaust gas temperature has been the deciding factor for a gasoline engine with a variable geometry turbocharger, which Porsche is currently developing.

m;

It is absolutely correct that Russ has lubricating properties. Everyone who owns an oven knows this ( ). But between us. I have cleaned several VTG burners, and they all still work today. However, in the pictures I have seen and also published (here), the lubricating effect has been exceeded. So much soot has accumulated around the edges of the nozzles that the nozzles closest to the manifold connection have become immobile. Soot or lubrication, it's a matter of balance. As long as you don't verschandeln it too aggressively and leave scratches where soot can accumulate, that's a first step. If other clues are found, one can also follow those.


Otherwise, I'm going to assume that not nearly as much lubricant is needed. Even though I'm not an expert on carbon, I've at least handled a VTG (vacuum tube gauge) before. The aspect is certainly present, but with the temperatures prevalent there, no amount of grease will help you.

Certainly, the absolute, undeniable reason for the absence of VTG (Variable Turbine Geometry) chargers on standard gasoline engines is the price. Then there's the material (again, due to price). I believe lubrication is much further down the list of concerns. How does Porsche do it? What elaborate processes are they using for these minimal movements?

I would also be interested in information about that, even if it doesn't help the author here.

Here's my advice when all other options have been exhausted: Soak everything in rust remover overnight and then disassemble it. If you leave the running gear alone, these types of loaders are absolutely easy to clean. Normally, the problems then disappear.

It is absolutely correct that soot has lubricating properties. Everyone who owns an oven knows this ( ). But between us, I have cleaned several VTG (variable geometry turbochargers) and they all still work today. However, in the pictures I have seen and also published (here), the lubricating effect has been exceeded. So much soot has accumulated at the edges of the vanes that the vanes closest to the exhaust manifold connection have become immobile. Soot or lubrication, it doesn't matter. As long as you don't verschandeln it mechanically and leave scratches where soot can settle, that's already a first step. If one finds other clues, one can also follow those.

Many people here have already had experience with malfunctioning VTG chargers. The manufacturers have to spend many millions of euros annually on goodwill and warranty costs related to defective VTG chargers. It definitely can't always be just about cleaning the VTG mechanism.

How is it actually possible for you, within a system of over 10 moving parts with countless contact points between them, to precisely locate the exact spot where something is jammed? Or perhaps a significant amount of soot hadn't accumulated on the aforementioned shovel because it was already stuck somewhere else, and the engine was running too rich for a while, resulting in excessive soot emissions.

Otherwise, I'm going to assume that it doesn't actually need that much lubrication. Even though I'm not a carbon fiber expert, I've at least held a VTG before. The aspect is certainly there, however, given the temperatures prevailing there, no amount of grease will help you.

VTG failures often occur because excessive material transfer has built up on a metal-to-metal contact surface. The presence of lubricant between the contact surfaces reduces both the material transfer and the friction. The resin should retain its lubricating properties until it is completely burned off.

Certainly, the absolute and real reason for the absence of VTG (Variable Turbine Geometry) chargers on normal gasoline engines is the price. Then there's the material (due to price). I believe lubrication is much further down the list. How does Porsche do it? What elaborate processes are they using for these minimal movements?

I would also be interested in information about that, even if it doesn't help the author here.

'Today, there are manufacturers who install not only a wastegate turbocharger, but also a mechanical supercharger with a clutch, and this is being done on an engine that is produced in relatively high volumes. Are you absolutely certain that the cost is the primary reason for using a variable turbine geometry (VTG) turbocharger on a gasoline engine? In my opinion, the long-term durability cannot be guaranteed yet.' Anyone who looks at the VTGs (variable turbo geometry) on diesel engines and their failure rates will inevitably come to the same conclusion.

Porsche extends the durability of its products, among other things, by increasing various parameters and tolerances. However, this always reduces the efficiency of the turbine. For a 3.6-liter engine, that might still be feasible, but for a 2.0-liter engine in a 1.8t vehicle, the extra cost of a durable variable turbine geometry (VTG) turbocharger might not be worth it anymore.

matthiasTDI96 wrote:

I would also be interested in information about that, even if it doesn't help the author here. Here's my advice when all other options have been exhausted: Soak everything in rust remover overnight and then disassemble it. If you leave the running gear alone, these types of loaders are absolutely easy to clean. Normally, the problems then disappear.

Hi!
Don't worry about that.
I'm sure I've been through much worse before. I just wanted to know if it's possible, and if so, how.
or whether I should just get a different charger.
VW would have probably been happy to sell me a turbocharger for 732.65.
But if I were to somehow manage to get another two years out of this cleaning process, that would be about...
20,000 km, that's quite a distance... definitely worth a try.

And for lubrication:
I imagine that most of the carbon (char) will burn away again, leaving behind other materials.

If I verschandeln our oil heating boiler tomorrow, I'll also remove a bucket of light ash/slag, but no soot.
These are likely to be sulfur compounds.
It's likely that other substances will interfere with the mechanism inside the loader, causing it to become blocked.

I once had a brake pad lubricant from Makra; it was some kind of ceramic lubricant, something with a temperature resistance of 1600°C.
Would that be a preventative measure?

Why wouldn't the stuck part be immediately apparent? If you have a VTG (Variable Geometry Turbine) in your hand, and you've already removed it from the turbine housing using the three screws, you remove the adjustment ring, and at that point, most of the blades will usually respond immediately to movement, except for one or two. The others will be stuck. There's a range of stiffness, from slightly difficult to move to completely stuck. Therefore, the "diesel bath" approach, as violence is not the solution.

Of course, there are other defects as well, that's quite obvious. However, the discussion was about cleaning. If you have an open loader in front of you where the running gear is damaged, cleaning won't solve the problem. Similarly, excessive gaming is also a problem.
If I understand the author correctly, he wants to explore all possibilities first, as turbochargers are not among the cheapest parts.

It is perfectly clear that excessive oil consumption can also indicate problems with the engine, and I have never doubted that.
My experience shows that cars that have been primarily used for short trips (often owned by older people) frequently develop faulty alternators after 100,000 km or more.

I don't know what the reasons are, at least not exactly. What I do know is that parts that cost more than others, even if they offer advantages, often face a more difficult path to being included in a product line.

You're referring to the TSI concept. Yes, that's an exception. Here, a small wastegate turbocharger is coupled with a compressor. The wastegate limits the operating range, hence the narrow operating range. Otherwise, this concept falls under the aforementioned exception. However, even a VTG loader installed here in the future would not be able to operate as effectively.

It's true that VTG loaders will likely be available in volume gasoline stations soon, and I agree that further research and development is needed to optimize their potential.
See diesel engine development.

I have previously been responsible for a VTG (Virtual Training Generator).

It still had an adjustment range of a maximum of 5mm on the outer lever, and within that range, it felt rough and stiff, like it was full of rust.

After driving the car a few hundred kilometers to my place, I wanted to remove the turbo and, "just for fun," I pressed the lever: It had the full adjustment range and it moved very smoothly.

Sometimes (but probably only with minor issues), "really pushing it" can help, meaning frequent load changes (a lot of shifting) and full throttle (high speed).

m;