NOACK relative to miles that oil is used

[slo town]

Hello:

I drive BMWs and need a LL-01, MB 229.5, A3/B4 oil. This spec, or combination of specs, mandates a NOACK of under 10%.

How is NOACK measured? What measure(s) determine the sub-10% value? Let's take two extreme cases; 1) the oil quickly loses 10% of its volume in the first hundred miles or 2) the oil gradually loses 10% of its volume over an OCI interval of, say, 5K miles?

And, what determines NOACK? What is the definition? Volume? Viscosity?

Thanks in advance,

Scott

 

[edyvw]

I would say it is ASTM method.
When it comes to NOACK, I think it is OCI interval. Evaporation loss in particular OCI interval. My best guess!

 

[Pontual]

10% over the duration of the Noak test by ASTM D5800 norm. I think it is 1 hour at 250 C. Nothing to with mileage.

 

[slo town]

Originally Posted By: Pontual
10% over the duration of the Noak test by ASTM D5800 norm. I think it is 1 hour at 250 C. Nothing to with mileage.


I am not doubting you, but can someone please collaborate this? This is the behavior I am seeing with an oil I used previously in both my BMWs (not the Castrol in my signature). I see rapid oil volume loss after an oil change, 2/3 to 3/4 quart after just 100 miles, then it stabilizes and uses no oil for the rest of the OCI.

I also saw a 9.1% increase in viscosity for a VOA compared to a UOA with just 128 miles on it - Blackstone reports, same batch of oil!

Should this be considered normal given Pontual's comment? Not throwing stones at you, Pontual.

Thanks,

Scott

 

[Shannow]

Scott,
Pontual is correct, it's 250C for an hour, with airflow across it.

It's designed to simulate what happens in the ring belt and cylinder walls, thus the temperature and the airflow.

Your oil consumption trend "feels" like NOACK could describe it, but I don't think it's that simple in practice, as the number is whatever is happening on the evaporation curve at the 1 hour mark, the process could still be progressing after that.

 

[Gunguydin]

Mabey it stabilizes at the level that your enging "likes" to be at. I have a Subaru that likes the oil level at 1/4 inch below the FULL mark on the dip stick. If I top it off to the FULL mark, the level will quickly drop to about 1/4 inch below full and then stay there.

 

[Joe90_guy]

One of the things you need to bear in mind is that the Noack test was pulled together by a Herr Doktor Kurt Noack in something like 1938! The Noack test is a very crude measure of fresh oil volatility. It doesn't 'simulate' anything per se.

 

[Shannow]

Originally Posted By: Joe90_guy
One of the things you need to bear in mind is that the Noack test was pulled together by a Herr Doktor Kurt Noack in something like 1938! The Noack test is a very crude measure of fresh oil volatility. It doesn't 'simulate' anything per se.


yeah, OK...

was more as theres a meme on BITOG that NOACK means nothing as bulk oil temperatures are only 100C or so.

It's not even very good at predicting one of it's uses, phosphorous transport to the catalyst.

 

[Joe90_guy]

Originally Posted By: Shannow
Originally Posted By: Joe90_guy
One of the things you need to bear in mind is that the Noack test was pulled together by a Herr Doktor Kurt Noack in something like 1938! The Noack test is a very crude measure of fresh oil volatility. It doesn't 'simulate' anything per se.


yeah, OK...

was more as theres a meme on BITOG that NOACK means nothing as bulk oil temperatures are only 100C or so.

It's not even very good at predicting one of it's uses, phosphorous transport to the catalyst.



You can actually find Kurt Noack's original paper on Google. As I recall, it even has a bit of authentic, old German Gothic font about it. My German is rubbish so there's no way I could ever read the paper but if I were to hazard a guess, I'd say the test is rooted somewhere in aero-engine operation. It you think about it, old Dr Porsche's 'Volksauto' (what went on to become the Beetle) was still in it's infancy. It's purpose was always more to con the gullible German public out of their savings than to advance automotive science. So a test arising from research into aero-engine oil systems might make more sense.

 

[Shannow]

LOL

 

[Garak]

Originally Posted By: Joe90_guy
The Noack test is a very crude measure of fresh oil volatility. It doesn't 'simulate' anything per se.

If I recall correctly, it was before you started posting here that Valvoline was grousing that the Noack testing has reproducibility issues, when one of their products was at the API limits during a PQIA spot check. I suppose when you're skirting the maximums, reproducibility could be a concern.

 

[JXW]

Originally Posted By: SLO_Town
Hello:

I drive BMWs and need a LL-01, MB 229.5, A3/B4 oil. This spec, or combination of specs, mandates a NOACK of under 10%.

How is NOACK measured? What measure(s) determine the sub-10% value? Let's take two extreme cases; 1) the oil quickly loses 10% of its volume in the first hundred miles or 2) the oil gradually loses 10% of its volume over an OCI interval of, say, 5K miles?

And, what determines NOACK? What is the definition? Volume? Viscosity?

Thanks in advance,

Scott


I have a 2010 328i with Redline 5w40 installed. Per the oil display when the car is hot and running full temp, the reading is exactly at the full line. This is with about 1500 miles on this interval.

A note, when I purchased the car, the dealer oil was low per the display and this was at end of a 10 interval or more.

I believe the 5w40 Redline to be slightly heavy (hths 4.0 or higher) so planning on redline 5w30 next oc.

I have no experience with Castrol unless we go back to 1998 and a Passat with VR6 using Castrol 5w40--I liked it then.

 

[Joe90_guy]

Here we are. The original 1936 paper by Herr Doktor Kurt Noack!

http://onlinelibrary.wiley.com/doi/10.1002/ange.19360492504/abstract

Most of the technical German is beyond my capabilities but I did manage to translate 'Prüfung fur die stinkende Schnellergäse durch der Grosser Arschloch Ring' as 'Test for contaminated high velocity blow-by gases through the large ring gap' so this is definitely the correct paper.

 

[ARCOgraphite]

Most oil usage on an otherwise healthy water-cooled engine is due to ingestion of fogged oil through PCV; next by combustion in the chamber through the mechanism of passing by gummed, stuck rings in one or more cyls.

 

[edyvw]

Originally Posted By: SLO_Town
Originally Posted By: Pontual
10% over the duration of the Noak test by ASTM D5800 norm. I think it is 1 hour at 250 C. Nothing to with mileage.


I am not doubting you, but can someone please collaborate this? This is the behavior I am seeing with an oil I used previously in both my BMWs (not the Castrol in my signature). I see rapid oil volume loss after an oil change, 2/3 to 3/4 quart after just 100 miles, then it stabilizes and uses no oil for the rest of the OCI.

I also saw a 9.1% increase in viscosity for a VOA compared to a UOA with just 128 miles on it - Blackstone reports, same batch of oil!

Should this be considered normal given Pontual's comment? Not throwing stones at you, Pontual.

Thanks,

Scott

Actually he is correct. Last night after I posted that I remembered PDS's that specified that it is 250c over one hour period.

 

[slo town]

Thanks for all your replies. Very helpful. This is beginning to make sense but I do not like what I saw with this latest brand of oil I tried (NOT the Castrol in our signature, Castrol seems to "behave").

I asked this question on the Passenger Car forum this morning. Just to gain further perspective. FWIW.

Scott

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4068218#Post4068218

 

[slo town]

What would you guys think if viscosity increased significantly after just 128 miles of usage?

Blackstone oil analysis.

VOA 40C 89.81, 100C 13.82
UOA 40C 87.19, 100C 15.08
Also, this oil had been used in this vehicle for the last 15K miles. The above UOA was the fourth change using this oil, not a switch from another brand or weight.

I am going to start a new thread with VOA and UOA reports, and a methodical description of my observations. I was just trying to understand certain things before posting the VOA and UOA because I think they could be controversial. I wanted to do my homework first.

Scott

 

[drtyler]

I would not assume that the lab's readings are accurate either.

 

[Quattro Pete]

Originally Posted By: drtyler
I would not assume that the lab's readings are accurate either.

True. I would have blackstone retest both samples, but even then, there is no guarantee.

 

[slo town]

Originally Posted By: drtyler
I would not assume that the lab's readings are accurate either.


I hear you on that, though I am trusting them. This is why; with the oil in question I have to add 2/3 to 3/4 a quart within the first 100 miles after changing. This happens consistently since I started using this oil about 18 months ago. It happens with both our BMWs. I have never had to add oil after an oil change of German Castrol 0W030 (which both cars "grew up on"), or the German Castrol 0W-40 which I switched both BMWs back to last weekend.

It is a fact that this other oil shows 2/3 to 3/4 a quart loss on both BMWs - and this loss occurs within 100 miles. I know I cannot prove this, but you have to trust me. I still have two 5 liter jugs of this suspect oil. If I had to prove it in court, I have the oil to do so. I'm not throwing stones, but I can prove it if I had to.

So while I hear you on the reliability and precision of the oil analysis results, I think you have to agree the combination of oil consumption and viscosity change lends support to the accuracy of the oil analysis.

Viscosity change because of sludged motors is not an issue because our two BMWs, and all our vehicles, are consistently maintained with short OCIs and have been since new.

Everyone's comments are appreciated.

Scott