Turbocharger Replacement: High Oil Consumption

Hello.

VW Caddy, 1.9 TDI, 105 hp, BLS engine.

For background information: This repair was last performed on this engine (the turbocharger manifold gasket was replaced): https://community.dieselschrauber.org/en/viewtopic.php?p=247449#247449

After another 25,000 km, the engine is worn out. A large amount of exhaust fumes are escaping through the oil filler cap, and everything on the exhaust side is oily. The emissions test cannot be passed in this condition, as you can also clearly smell burnt oil.

On the two cylinders on the left, facing the transmission, the channels all look like the one in the picture. More photos are attached.

The last 20,000 kilometers were driven on long distances at 2200-2700 RPM. Only 5,000 kilometers were a mix of short trips and full throttle. However, the "problem" has been occurring for approximately 15,000 to 20,000 kilometers.

The shaft of the charger feels smooth and free of play, and consequently, no metal shavings can be found anywhere. (Oil is still present in the charger's oil circuit.)

How likely is it that the turbocharger has been damaged?

Sure, no problem! Here's the translation:

"Thank you again!"

Images.

Hello,

"There should be no noticeable play in the axial direction, and only very little in the radial direction. The turbocharger shaft should rotate freely and without binding, even under radial load."
Furthermore, the engine control unit should not contain any error codes related to excessively high or low boost pressure.
It makes sense to perform a test run before disassembling the unit in order to assess whether the turbocharger pressure control system is still functioning correctly.

I would only reinstall the loader if the given conditions are met and the compressor wheel is undamaged (not visible in the pictures).

Unfortunately, excessive oil consumption can cause the VTG (Variable Turbine Geometry) adjustment mechanism on the turbocharger to become clogged with carbon deposits, which can impair its control performance. However, only you can assess this.
Generally, it's always bad when the turbocharger has to ingest oil from the exhaust gases, because this leads to carbon buildup that can impair its function.

Quote:

Data: Caddy2KA, year 2006 (105 hp), 300,000 km mileage. Of that, the turbocharger has 130,000 km, the tandem pump has 5,000 km, the valve cover has 1,000 km, and the DPF has approximately 10,000 km. The boost pressure, EGR values, and coolant temperature are all within the normal range. The oily problem is estimated to last for approximately 30,000 - 50,000 km

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I can hardly imagine that the charger will still function properly with this.
If you're already getting a used engine, I probably wouldn't reuse the old turbocharger.

Best regards, Rainer.

Okay, thank you!

-The water flowed smoothly, and there were no unusual noises.
-The VTG (Variable Turbine Geometry) can also be easily adjusted without any resistance. There were also no unusual readings when accelerating or applying throttle. But now a test drive is out of the question...
-As far as I can tell, the compressor wheel is still in very good condition.

I will definitely take your advice about not reassembling it, so thank you very much for the advice!!! Perhaps there's a company that could disassemble the loader and inspect it.

Quote:

The VTG (Variable Turbine Geometry) can also be easily adjusted without encountering any resistance. When accelerating/giving gas, there were no unusual observations.

It actually suggests that everything is okay. Ultimately, you have to decide whether the risk is worth the potential savings.

Hi,
If oil is visible in the exhaust manifold's outlet channels, it's unlikely to be coming from the turbocharger located downstream. If it can also be attributed to individual cylinders, I suspect the problem lies in the cylinder head. It's likely that some of the valve stem seals are worn. This also corresponds to the smoke and the smell of burnt oil. Simply replacing the seals on the installed cylinder head may not be enough, as the valve stems themselves are probably also coated in oil residue. The only solution is to remove the cylinder head for a complete overhaul or replacement.
hg
Herbert.

Good morning!

The entire engine will be replaced with a used one with 139,000 km. The reason is that the old engine has already covered 324,000 km. Additionally, I was told that with VW engines, the valve seats often wear out to the point where simple grinding and machining wouldn't last long. In that case, much more would need to be invested to get it working properly again. That alone is barely acceptable. But the new engine comes with injectors. In general, I consider the entire mileage!

The engine has already been removed. It's almost easier than disassembling it into parts!

The turbocharger I'm referring to is approximately 165,000 km old. https://community.dieselschrauber.org/en/viewtopic.php?t=27007 It was replaced back then in the thread "Rück beim Beschleunigen."

Herbert wrote:

If oil is visible in the exhaust manifold's outlet channels, it is unlikely to be coming from the turbocharger located downstream in the exhaust flow

.
Okay. My concern was more about the possibility that the VTG (vacuum transmitter gauge) is clogged with carbon deposits due to the bubbling oil. If not, that's even better.
The problem is, it's frustrating when you've put everything back together, and the first full-throttle run ends up in the emergency mode.

The dealer's records showed where I purchased the turbocharger back then.

Economic total loss

-The VTG is slightly jammed.
- a defective seal
- Storage damage.

Cause: Possible blockage in the crankcase ventilation system!

Well, then that works.

Hi,
However, this contradicts your previous observations, except for the minor issue with the VTG coupling. The remote diagnosis of a "faulty crankcase ventilation system" is strange.
hg
Herbert.

"Doesn't one thing actually affect the other? If the valve stem seals are defective, wouldn't that create higher engine internal pressure? The crankcase ventilation system wouldn't be able to compensate for that, and oil would be forced through the turbocharger. Wouldn't the same thing happen with a blocked crankcase ventilation system?"

Or what exactly do you mean, Herbert?

Martininii wrote:

... If the valve stem seals are defective, then a higher engine internal pressure is created, right?

No, not necessarily. Oil leaks along the valve stems, either towards the intake or the exhaust. In your cylinder head, I saw two oil-stained channels, which is why I suggested checking the valve stem seals. If the crankcase ventilation is blocked, it will force its way out of all possible seals that are not normally under pressure (oil pan, valve cover, crankshaft seals).
In any case, the recommendation was to replace the charger along with the VTG if there was any suspicion of a problem with the VTG.
hg
Herbert.