Oil Pump Drive for 2.0 TDI Engines with Balance Shafts

In all 2.0 TDI pump-injector engines equipped with balance shaft modules, the oil pump is driven by an undersized hexagonal shaft.

In 2011, I explicitly inquired with Audi whether my engine in my Audi A6 was affected by the aforementioned problem, but unfortunately, my request was met with generic and uninformative responses.
Therefore, I now, in the year 2015, have the regrettable pleasure of documenting the damage and the repair of the crankshaft or, more specifically, the oil pump drive shaft.

Is there a trick to getting the two small screws at the back that go into the holes in the clutch bell? Are these identical to the front screws?

What a load of rubbish, you just can't get anywhere with it. I can be ripped off by other manufacturers too - and at a cheaper price.

dieselschrauber wrote:

Is there a trick for the two small screws at the back that you need to use to access the holes in the clutch bell? Are these identical to the front screws? What a load of rubbish, you just can't get anywhere with it. This was definitely my last Audi. I can be ripped off by other manufacturers too - and at a cheaper price.

Normally, they are usually 10mm hex bolts on the outside and 6mm Allen keys on the inside. Since it's often easier to access the gear-to-oil pan bolt at an angle, a "rounded" Allen key is used! The easiest way to lift the engine for oil pan removal is using a lifting table.

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Since it's easier to access the screw between the transmission and the oil pan at an angle, you use a "round" Allen wrench!

It didn't work; one Allen wrench was too short, and the other was too long. I now need to build something to raise the engine more than 2 cm.

dieselschrauber wrote:

Is there a trick for the two small screws at the back that you need to use to access the holes in the clutch bell? Are these identical to the front screws? What a load of rubbish, you just can't get anywhere with it. This was definitely my last Audi. I can be ripped off by other manufacturers too - and at a cheaper price.

Have you ever tinkered with a French car ? I could write a whole song about the problems . With almost all manufacturers, there are good and bad aspects here and there.

I've always found Audis too expensive, so I've been driving other VW Group cars for much less money – an A3 interior in a Seat body. What more could you want?

Since yesterday, I bought a 20-year-old OMA-G3 with an automatic transmission for a small price and with low mileage – THAT was truly simple technology!

dieselschrauber wrote:

Since it's easier to access the screw between the transmission and the oil pan at an angle, Quote: you should use a "round" Allen wrench! It didn't work; one Allen wrench was too short, and the other was too long. I now need to build something to raise the engine more than 2 cm.

Alternatively: You can use sturdy wooden beams and lifting straps to lift the object, or place a jack on the beams and use a lifting strap attached to the jack.

It probably looks something like that; a tow rope would also work! The picture is from my T3 conversion project.

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The worst thing is that this has been known for a long time at VAG, and now even common rail systems are supposedly affected.

... und auf konkrete Nachfrage verschweigen. Ein "Schauen Sie mal nach, wie der 6-Kant aussieht und wechseln Sie ihn bei Bedarf" wäre doch i.O. gewesen! What a bunch of jerks!

My trust in the juice store has completely vanished.

Hello.

I don't know if this will be helpful.

To better access the two rear screws on the oil pan, you need to rotate the flywheel. There are two recessed areas in the direction of travel where it's easier to reach with a wrench. If necessary, you may need to rotate the flywheel slightly further from one screw to the other before loosening it.

Regards, Mpire.

Thanks for the tip, I'll take a look. The sprocket is unfortunately in the way for me, but maybe there's a hole right in front of the sprocket...

"Edit: Using a ball-head Allen wrench of the correct length (my previous ones were either too short or too long), you can loosen the two screws that secure the oil pan to the clutch bell."
"Edit2: There are no holes behind the sprocket, so you don't need a special key to access it."

Best regards, Rainer.

Gear mechanism for driving the balance shaft module.

I found a tooth flank play value of 0.038 to 0.072 mm online, but unfortunately, I couldn't find a reliable source for this information. Can anyone confirm these values?

Background: After now 221,000 km, the gears feel okay in terms of play, but I see room for improvement because of the slight wobble of the balance shafts and the noticeable play that can be felt by hand. The gears themselves look good.

The "adjustment" of the game is standardly performed by using a wear layer on a new intermediate wheel.

Best regards, Rainer.

from the Regional Logistics Center to the Joint Command and Control Directorate.
New balancer module:
- The helical gear drive of the balance shaft module must be installed with a tooth flank clearance of 0.038...0.072 mm.
To achieve the correct tooth flank engagement, a coating of appropriate thickness is applied to the new pinion gear.

Used balancer wave module:
- If the screw for the intermediate gear has been loosened, or if the front gear on the crankshaft or the crankshaft itself has been replaced, a new intermediate gear must be installed.
- The intermediate gear must have a clearly noticeable amount of play when rotated.

No information provided regarding wear limits.

Could you please take some pictures of the oil pump and how the shaft interacts with the balance shaft module? It seems like they are still using the six-point socket.

It's quite nonsensical to connect two shafts using a hexagonal coupling. This design makes it difficult to manage axial displacement and parallel misalignment. Either it will bind and vibrate, or it will jam. A splined shaft with an internal/external configuration (with a ball or ellipsoid) would be a much better solution.
We actually learned that with the Märklin construction kit.
hg
Herbert.

Hello Herbert,

I have inserted the image of the recording above.

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One might think they are still using the hex socket screws.

Yes, but with approximately twice the exposure time in the wave. If it then fails after 442,000 km instead of 221,000 km, that would be something one could live with . Based on experience, a "weak point" is usually intentionally introduced elsewhere for this purpose...

Best regards, Rainer.

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Yes, but with approximately twice the duration of interaction with the wave.

That's not helpful. It results in an increasingly rigid connection with an over-determined system and less flexibility.

hg
Herbert.

What about the first common rail engines? Detailed information is scarce; some sources claim that these are also affected, while others argue that this problem no longer exists in them.

Is there a specific known case where the oil pump hexagon socket on a crankshaft (CR) has been stripped or rounded off?

According to Wild Motors' list, some (early) CR TDI models are affected.
http://wildmotoren.markuswild.de/index.php?PID=Fahrzeuge

Best regards, Rainer.

dieselschrauber wrote:

Quote: The worst thing is that this has been known for a long time at VAG, and it's even supposed to affect common-rail systems. ... und auf konkrete Nachfrage verschweigen. Ein "Schauen Sie mal nach, wie der 6-Kant aussieht und wechseln Sie ihn bei Bedarf" wäre doch i.O. gewesen! What a bunch of jerks! My trust in the juice store is completely gone.

Hello Rainer,

It's a shame that you are now also among those affected. It's truly unbelievable how customers of the VAG Group are being treated like fools. I experienced it in March 2013 with my A4 Cabrio (3.0L V6 TDI) at a mileage of 119,000 km. What started as a head gasket failure turned into a complete engine failure due to scoring and seizing in all six cylinders. Even with the Audi Thermal Management system, things didn't improve. Since the installation, there have been vibrations, lack of power, and loss of performance. Now, at the end of March, three defective injectors (MWB 072-077, showing a maximum negative value of -4ms) were found and replaced with a complete set of six. The vibrations returned after only 3,000 km, and now there's also a noticeable wobble. In addition, the engine has been slowly losing coolant for the past 20,000 km. And all this happened with only 60,000 km on the clock. I have owned VAG vehicles since 1980, but I have never experienced such poor design and quality.

What's alarming is that almost all engines from 2005 onwards seem to be affected by such design flaws. In some cases, it's piston slap (3.2L V6), in others, the timing chains tear (4.2L V, or defective injectors dilute the oil so much that it leads to cylinder bore wear (3.0L V6 TDI). In TFSI engines, incorrect pistons were installed, and the engines consume oil like a Trabant, which can lead to engine failure due to spark plug fouling.
All of these defects are known to the corporation, and they are simply ignoring them and remaining silent. Customers whose engines fail during the warranty period receive a new one. Afterwards, affected customers may be offered some compensation by the company, while the rest are left speechless and forced to either pay for the engine repair themselves or scrap the car. During my visits to junkyards, I am constantly surprised by how many visually flawless Audis and VWs are there with engine problems, usually around six to seven years old, all representing total economic losses because the prices for replacement parts for engines are simply too high.

Looking at the mileage of my older VW Group cars, it seems something is going seriously wrong within the VW Group right now.