Oil Cross: Meaning & Symbolism Explained

Hello everyone,

Not long ago (at 15,000 km), I was criticizing the oil from a particular manufacturer due to its very high consumption towards the end of the cycle. Later, in the new interval, I was praising a different oil because there was no noticeable consumption initially.
Now, at 3,000 kilometers before the next oil change, it's starting to consume oil again like a staunch CSU voter. (meaning: 0-12,000 km - less than 0.5 liters of oil consumption; 12,000-15,000 km - up to 1.5 liters of oil consumption).

The driving route and driver profile remained the same during both testing periods. The tests were conducted under temperature cycling conditions, simulating summer and winter conditions -> no difference was observed.

The car is running without an EGR valve, but with a generous amount of fuel additive.

I don't know if I've only become sensitive since the AGR and 10ct measures, or whether this phenomenon existed before.

Someone told me in an old thread that the long carbon chains in the oil would simply break down over time and be burned along with everything else.

Does anyone else notice an exponentially increasing oil consumption depending on the distance traveled within a given interval?


Thank you very much.

Tobias.

Hmm.

I'm not sure, but I always felt that I could control the oil consumption by adjusting the engine speed.

"Driving at a maximum of 140 km/h on the highway results in very low fuel consumption. However, driving much faster with frequent acceleration consumes significantly more fuel."

The oil is likely leaking through the turbocharger in my case (the shaft has some play, and the compressor side is noticeably oily).

m;

edit: but 1.5 liters per 3000 km is NEVER the case.

In December, driving 5000 km in a week resulted in a maximum fuel consumption of 1 liter per [unit of distance - e.g., 100 km].

The higher the engine speed, the more the oil heats up over time and becomes thinner.
and therefore burns away more quickly. Towards the end of the cycle, the effect is greater.
to notice.

Meine Erfahrung vom letzten Jahr bei 14000KM des Öl Zyklus 0,5 l/1000km. However.
I also drove 30% of the distance at 180 km/h. The oil change interval is every 15,000 km.
Switched to a different product from the same brand, and it went back to normal at 120 km/h, so the problem was likely related to the previous product.
and after 5000 km, there is still no significant oil consumption.

I had very similar experiences with my G3 throughout its lifespan (see below), but never consumed as much as 1.5 liters per 3000 kilometers.

With my current PDs, I haven't been able to observe this yet (due to low mileage).

However, I always used mineral oil (Castrol GTD 10W40) in the G3, while I only used synthetic oil in the PD.

'Wear and tear' is normal in mineral oil because it's composed of molecules of varying sizes, while synthetic oil has molecules of the same size.

Hello,

It's often the turbocharger in TDI engines. Let's wait and see how it develops...

Best regards, Rainer.

Thank you for your responses.

I can also confirm that my heating system contributes to the high energy consumption.

I'm also going to open up the turbocharger from the compressor side and take a look, because during my EGR modifications and inspections, I already diagnosed an oily, slimy contamination on the valve, not a coke-like, crumbly one. It's more like a hard deposit, as described by many others.

Certainly, thank you.
Nice WoE.

Hi,

The shortening of the molecular chains is correct. Also, over time, the VI improvers (additives that cause the oil to swell when heated in order to maintain viscosity) are consumed.
In addition, aggressive driving leads to increased oil vaporization losses at high temperatures (cylinder walls, piston skirts), which also increase over time as the oil thins out. In particular, 0W and 5W oils have higher vaporization losses.

Hello,

Now, I'd like to add my two cents on the topic of oil consumption as well.

Here's the translation:

With my AFN, it's like with Dieselmartin. My turbo also uses a lot of oil, so it's not uncommon for me to have to top up 2 liters (sometimes even more) during an interval, even when I'm careful with how much I accelerate . When I read about the oil consumption of others in this forum, I think that's quite a bit.

However, with my old CY, I experienced a phenomenon that I still can't quite explain. During my military service, it was most pronounced. Although I only drove about 400 km per week, the fact that soldiers are eager to get home as quickly as possible after work on Fridays (keyword: NATO-Ralley ) resulted in a corresponding driving profile. I almost exclusively drove on country roads and had to downshift very frequently (for overtaking, etc.). This driving style meant I sometimes had to top up the oil by up to 2 liters per month. However, when I went on vacation and 'drove' the CY (almost exclusively) with the accelerator pedal flat to the floor for 1200 km on the highway, I didn't use a single drop of oil . And so, one could almost 'calculate' the oil consumption: The more gear changes and acceleration phases there were, the higher the oil consumption. With the TDI, I haven't quite figured out how to influence this (at least with my oil-guzzler); it simply takes the amount of oil it needs .

Hi!

Also mein AFB nascht auch nach 10tkm nen halben Liter! Und bleibt dann auf dem minimierten Stand! Und das mit 0W-30! No long-life products!
Driving profile - very varied! But always make sure to warm it up properly before driving!

Hello Bee.

Oil in the compressor of the ATL does not always necessarily indicate a leak in the ATL reservoir. Rather, the oil comes from the crankcase ventilation system, which is fed into the compressor.

Yes, I can confirm the experience that increased heating plus older oil leads to higher oil consumption. When I once drove over 500 km on the highway at night with an old fill of Castrol GTD 10W40 (oil level at the minimum mark) to visit my parents, the oil level was already below the minimum mark there. Of course, I changed it there.

What I cannot confirm is that fully synthetic 5W40 oil has more losses than semi-synthetic 10W40; in fact, the opposite may be true.

'I've been using full synthetic 5W40 Kaufland oil since kilometer 93,000 and have never had such low oil consumption. It's time for an oil change soon; the new Kaufland oil is already here. It costs €19 per 5 liters. Hopefully, we'll have some nice weather soon! I also have a new XXL oil filter; it's 25cm tall. I actually wanted to use it as a fuel filter (biodiesel friendly), but that would have required extending the fuel lines. (It was already touching the hood where the fuel filter is located).'

Regards,
Holger.