Diesel in Engine Oil: Causes and Solutions.

Hello!

I had the engine oil of my Audi (common rail; 3.0 TDI (ASB)) analyzed.

The following values appear to be elevated:
228 mg/kg iron.
6.55% diesel content.
4.29% biodiesel content.


I'm particularly concerned about the high proportion of fuel used.

How can such a high value be achieved?


Oil change mileage: 29,000 km. Total vehicle mileage: 91,500 km.



Sure, here's the translation:

"Thanks."
Michael.

Post-injection for DPF regeneration?

It's a simple issue: you're driving too many short distances. Try taking longer trips; that might help reduce the amount of diesel fuel diluting the engine oil. The best solution to avoid engine problems is probably to change the oil more frequently.

We used to change the oil every 10,000 to 15,000 kilometers, but the "longlife" oil promises almost indefinite use, and besides, you're supposed to buy a new car eventually.

I've only had the car for three months.

According to the previous owner (who had driven 20,000 kilometers with that oil), they drove a long distance on the highway at least once a week.


I myself (now with 10,000 km on the "on Tour" oil) have been driving a short distance daily for about three weeks (two trips of 2 km each with a cold engine), but interspersed with that are also stretches of 50 to 200 km at a time.

I can't imagine that such a large proportion comes from this.


Could the injectors be defective?

Certainly, something could be defective that's causing the diesel content to increase, but I still wouldn't hesitate too long and would change the oil. You usually only recognize a mechanically defective part after an autopsy .

Whoever drives 30,000 km without an oil change is to blame for that , regardless of the LL (Longlife) specification.

If it's supposed to be done at 30,000 km, I will use that service as well .


I just went to the Audi dealership. Nothing came of it except for an appointment for an inspection next week.


How are my injectors doing?
Are these components likely to be coked due to consistently high temperatures?

Zero-point calibration.
Cylinder 1: 30.0 ms | 42.0 ms | 16.0 ms (Activation duration for calibration points 1 to 3)
Cylinder 2: 24.0 ms | 22.0 ms | 16.0 ms
Cylinder 3: 28.0 ms | 34.0 ms | 12.0 ms
Cylinder 4: 30.0 ms | 42.0 ms | 18.0 ms
Cylinder 5: 22.0 ms | 44.0 ms | 8.0 ms
Cylinder 6: 24.0 ms | 30.0 ms | 14.0 ms

The current average biodiesel content of 7% is calculated across the total volume of diesel sold. Therefore, it is common to find both lower and higher percentages of biodiesel.

If you use low-quality fuel, it can lead to a high amount of fuel entering the engine oil during DPF regeneration. This is because the biodiesel component, which is injected late in the combustion process, may not burn completely and cannot be fully removed from the oil.

-> Use premium diesel or kerosene with a lubricant additive, or only drive long distances, or change the oil more frequently .

Approximately 10% wear particles in the oil when reaching the oil change interval is normal. Oil degradation due to frequent short trips is also normal. This seems more indicative of short trips rather than long distances. Certain fractions and native cracking components do not tend to evaporate under the conditions in the combustion chamber or crankcase; they remain stable at a given concentration. This is not comparable to what you find in gasoline engines. Even there, distillates can be detected in the oil despite long driving distances. Therefore, no defect can be attributed to your engine. Everything is fine.

"In gasoline engines with 1.8T engines, I often observe a large amount of oil sludge buildup on the valve cover. Sometimes, simply examining the oil filler cap is enough to conclude that the owner has skipped oil changes."
Recently, there have been significant problems with oil supply in LL cars.

In the case of gasoline engines with the 1.8T engine, I often observe a large amount of oil sludge buildup on the valve cover. Sometimes, simply examining the oil filler cap is enough to conclude that the owner has skipped oil changes.
Recently, there have been significant problems with oil supply, especially in LL cars.

But that's only due to the inferior oil. It's fully synthetic, and there are no deposits.

If that's supposed to happen at the 30,000 km mark, I'll do it too icon_wink.gif

Do you also wash yourself every day with the same water, or do you sometimes use fresh water?

LL oils are actually of a higher quality, or at least that's what their prices would suggest.
Okay, a 30,000 km service interval is simply too long, unless you drive it all at once .

LL oils are synthetic, which means they can be more precisely defined. What makes synthetic oils so expensive is the additives. Nothing else. Synthetic oils have the disadvantage that certain fractions are not age-resistant. This is where the added additives come in. Because these additives are expensive, oils with corresponding alloy components cost accordingly.

synthetic, semi-synthetic, fully synthetic - what does it all mean?
Full synthetic oils do not contain any mineral base oil, which slightly improves their performance.

5W30 LL3 is not fully synthetic; at least, there are very few that are.
Generally, Volkswagen recommends using fully synthetic oils with a viscosity of either 0W-40 or 0W-30.
The cleaning effect, which means keeping as many particles as possible suspended or trapped in the filter, is best with VS systems – I think that's what Mullemaus meant.
The LL3 is supposed to be able to do everything and also be cheap, but that's probably not possible.

Diesel_Rudi wrote:

LL oils are synthetic. That means they can be defined more precisely. What makes synth oils so expensive is the additives. Nothing else. Synth. oils have the disadvantage of not being age-resistant in certain fractions. This must be corrected by the added additive. Since these are expensive, oils with corresponding alloy components cost accordingly.

Hi Rudi,
Where does this knowledge come from?

"LL" has very little to do with being fully synthetic. As Klaus already mentioned, "5-W XX" is usually a hydrocracked oil, which means it's likely an LL2 or LL3 grade oil.
"The production process of synthetic oils, along with the additives, are the main drivers of cost (along with certifications...). "
c- Synthetische Öle sind nicht altersbeständig? Im Vergleich zu was? Tutanchamun? Grand Canyon? Oder min. ÖSure, here is the translation of the text from German to English:

"len?"

haithamina

(Are we talking about modern high-performance engines, or have I missed something?) Modern longlife oils are typically hydrocracked synthetic products of certain fractions. It's difficult to achieve the required kinematic viscosity with normal distillates that can withstand the conditions in the combustion chamber. This would lead to excessive wear. This deficiency cannot be remedied with a corresponding additive package, as this would require a significantly larger proportion than 20%. The addition of additives is more expensive than producing hydrocracked synthetics with lower quality base oils. However, hydrocracked synthetics can be easily adjusted. They still require a significantly larger additive package compared to mineral oils in order to make them resistant to aging. Because defined cracked oils (mostly long-chain molecules) are prone to oxidation and thus degradation under temperature influence, and lose their lubricating properties through cracking, antioxidants must be added accordingly.