Can Engine Oil Help Prevent Carbon Build Up?

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Valvoline just won't answer the question. Apparently Jason Fenske couldn't get an answer either.

In reducing IVD's, you want low SA, low volatility. Valvoline ME has a higher Noack than their other oils @ 12% and does not report SA like the other oils. As mentioned before, I have a feeling that this oil is designed to have higher Noack (12%) and somehow clean via its possible ester content.

Oils like Mobil 1 have a lower Noack (ex - M1 0w20 EP 10%) and a SA of .8. Different approach.
 
watch the savage geese vid "the realities of direct injection" for the real truth!! there "may" be some truth to Valvolines advertising, BUT prolly more typical HYPE + advertising BULLPOOP. manufacturers have been + continue being moot, but meanwhile some are implementing BOTH injections which of course is COSTLY.
 
One of the reasons the motor oil vendors don't want to answer the question definitively is that not only does the NOACK volatility of the oil make a difference, but so does the drain interval. With lower OCI intervals being more damaging than long drain intervals.

Of course it would be against the commercial interests of the motor oil vendors to specify significantly longer drain intervals for their products unless they felt that their particular market positioning facilitated such.
 
Of course Valvoline and other oil companies aren't going to say that their oil definitely reduces carbon buildup. That would open them up to liability.
 
Originally Posted by pitzel
One of the reasons the motor oil vendors don't want to answer the question definitively is that not only does the NOACK volatility of the oil make a difference, but so does the drain interval. With lower OCI intervals being more damaging than long drain intervals.

Of course it would be against the commercial interests of the motor oil vendors to specify significantly longer drain intervals for their products unless they felt that their particular market positioning facilitated such.


You're saying more frequent oil changes cause more intake tract buildup?

How so?
 
Originally Posted by buster
Mods, can this post be added to the post below?

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3225789/1

Penzoil in regards to intake valve deposits and oil and what not: Oil volatility is not a significant factor for inlet valve deposits in a direct injection gasoline engine.

This is correct. I have been repeating and repeating this:

What comes through the PCV is liquid oil mist, not evaporated oil vapor. Therefore, Noack volatility has no direct effect on the intake valve deposits (IVD).

Factors affecting IVD: Sulfated ash (SA) level (the lower the better), VII amount (the less the better) and type, antioxidant amount (the more the better) and type, detergents, dispersants, base-oil quality, etc.

Base-oil quality increases with decreasing Noack volatility for a given CCS (cold-cranking simulator) viscosity, but there is no direct relation as Noack also decreases with increasing CCS.

https://www.bobistheoilguy.com/foru...ngine-oil-and-valve-deposits#Post4854838
 
Originally Posted by john_pifer
You're saying more frequent oil changes cause more intake tract buildup?
How so?


Virgin motor oil, prior to significant in-service use, has the highest rate of evaporation. So when an engine is exposed to longer OCI's, less initial evaporation takes place under engine operating conditions, and hence, fewer intake valve deposits due to such.

The OEMs have invested considerable resources to prod their customers into using longer OCI's, *and* have mandated far higher quality oils that are less susceptible to early evaporation. They've also cracked down considerably on their own dealer networks that frequently filled cars with out of spec lubricants for cost efficiency or marketing purposes.

A big problem for the OEMs in replicating the intake building issues was simply replicating the issue. As OEM engineers simply could not fully appreciate how engines are maintained in "the real world" which often includes the use of poor quality lubricants changed overly frequently. When the topic came up a few years back, I did a post here where I meta-analyzed a several hundred page thread of an enthusiast forum in which there were complaints of the intake clogging -- every last complainer had a high likelihood of maintenance that was not per spec, ie: overly frequent oil changes and/or high susceptibility to lubricant fraud.

Quote
What comes through the PCV is liquid oil mist, not evaporated oil vapor. Therefore, Noack volatility has no direct effect on the intake valve deposits (IVD).


Of course there's evaporated oil vapor in the PCV gas stream. And if "Noack volatility" has no effect, where the heck does the oil evaporated in a NOACK volatility test end up, if not recirculated back into the intake.
 
Originally Posted by pitzel
Originally Posted by john_pifer
You're saying more frequent oil changes cause more intake tract buildup?
How so?


Virgin motor oil, prior to significant in-service use, has the highest rate of evaporation. So when an engine is exposed to longer OCI's, less initial evaporation takes place under engine operating conditions, and hence, fewer intake valve deposits due to such.



Of course there's evaporated oil vapor in the PCV gas stream. And if "Noack volatility" has no effect, where the heck does the oil evaporated in a NOACK volatility test end up, if not recirculated back into the intake.

[/quote]


But, what is the noack of oil as its constantly diluted with gasoline? Even after the initial volatility has vaporized, how does the fuel dilution contribute to further oil vaporization? Has anyone tested that?
 
Originally Posted by pitzel


Virgin motor oil, prior to significant in-service use, has the highest rate of evaporation. So when an engine is exposed to longer OCI's, less initial evaporation takes place under engine operating conditions, and hence, fewer intake valve deposits due to such.


Of course there's evaporated oil vapor in the PCV gas stream. And if "Noack volatility" has no effect, where the heck does the oil evaporated in a NOACK volatility test end up, if not recirculated back into the intake.



But, what is the noack of oil as its constantly diluted with gasoline? Even after the initial volatility has vaporized, how does the everyday constant fuel dilution contribute to further oil vaporization? Has anyone tested that?
 
Last edited:
Originally Posted by spasm3

But, what is the noack of oil as its constantly diluted with gasoline? Even after the initial volatility has vaporized, how does the fuel dilution contribute to further oil vaporization? Has anyone tested that?


Petrol would act as a solvent in such context, so fuel dilution, and recirculation of such through the PCV may reduce deposits. Although dramatically less so than port injection.

So fuel dilution that some brands experience may very well have a beneficial/protective effect.
 
Originally Posted by pitzel

Petrol would act as a solvent in such context, so fuel dilution, and recirculation of such through the PCV may reduce deposits. Although dramatically less so than port injection.

So fuel dilution that some brands experience may very well have a beneficial/protective effect.


In that case, there would not be intake valve deposits. Yet there are intake valve deposits, so i don't think that flies.
 
Last edited:
Originally Posted by pitzel
Originally Posted by Gokhan
What comes through the PCV is liquid oil mist, not evaporated oil vapor. Therefore, Noack volatility has no direct effect on the intake valve deposits (IVD).
Of course there's evaporated oil vapor in the PCV gas stream. And if "Noack volatility" has no effect, where the heck does the oil evaporated in a NOACK volatility test end up, if not recirculated back into the intake.

No, the evaporated oil in PCV is negligible. Evaporation rate increases exponentially with the temperature; therefore, almost oil oil evaporation happens at the cylinder liner.

In any case the Afton study I linked above showed that there is no major evaporation component to the intake-valve deposits (IVD). This was one of their main conclusions. The study discovered that the ratios of the elements in the IVD were the same as the ratios in the virgin oil, which wouldn't be the case if they were coming from oil vapors, as oil vapors only contain the distilled oil (primarily the base oil) and no additives. Therefore, they concluded that the main source of IVD is liquid oil. Moreover, when they disconnected the PCV, there were little deposits, and the ratios of the elements were different than in virgin oil, showing that unlike with the PCV connected, the source of IVD was not liquid oil when the PCV was disconnected. They also showed that the main source of IVD is PCV, as IVD decreased by 2/3 when PCV was disconnected.

I cannot post the whole paper due to copyright issues, but I posted its conclusions at the link above and below.

https://www.bobistheoilguy.com/foru...ngine-oil-and-valve-deposits#Post4854838
 
I've heard you say this a few times now. I was close to thinking I needed to change my oil more often but now I think I'm better off sticking with Honda's maintenance minded and any brand name synthetic.
 
Originally Posted by spasm3
Originally Posted by pitzel

Petrol would act as a solvent in such context, so fuel dilution, and recirculation of such through the PCV may reduce deposits. Although dramatically less so than port injection.
So fuel dilution that some brands experience may very well have a beneficial/protective effect.

In that case, there would not be intake valve deposits. Yet there are intake valve deposits, so i don't think that flies.


Its a question of severity. Just because petrol in the oil may be protective of, and facilitate a reduction in intake depositing opportunities, does not imply that intake deposits completely dissappear. Its probably not realistic to melt intake deposits away simply by adding a quart of petrol to your motor oil at every gas fill-up, for example. But if fuel dilution were eliminated in the engines that are known to have intake deposit issues, the incidence and severity of deposits may very well be increased.

Quote
They also showed that the main source of IVD is PCV, as IVD decreased by 2/3 when PCV was disconnected.


Evaporated oil goes through the PCV. So of course if you inhibit the PCV system, the evaporated oil cannot hit the intake valves. You can go onto YouTube (for example) and find examples of people emptying their catch cans -- the catch cans largely being filled with material that does not resemble normal crankcase motor oil, but rather a material with considerably less viscosity than what would be found in an engine. The engine effectively operating as a sort of fractional distillation apparatus, in combination with the recirculation of combustion byproducts that have leaked through the rings.
 
Originally Posted by Jake777
I've heard you say this a few times now. I was close to thinking I needed to change my oil more often but now I think I'm better off sticking with Honda's maintenance minded and any brand name synthetic.


Honda's have mostly avoided the issues because the ownership base is one of the most adherent to maintenance recommendations including the maintenance minders.

"Enthusiast"-focused car brands have fared the worst.
 
Originally Posted by pitzel
Originally Posted by Jake777
I've heard you say this a few times now. I was close to thinking I needed to change my oil more often but now I think I'm better off sticking with Honda's maintenance minded and any brand name synthetic.


Honda's have mostly avoided the issues because the ownership base is one of the most adherent to maintenance recommendations including the maintenance minders.

"Enthusiast"-focused car brands have fared the worst.


That actually makes sense. Hmm. I think I'm going to stick with the Maintenance Minder. I was even feeling guilty about following the every other filter change like they say. Any opinion on that?
 
Originally Posted by Jake777
Originally Posted by pitzel
Originally Posted by Jake777
I've heard you say this a few times now. I was close to thinking I needed to change my oil more often but now I think I'm better off sticking with Honda's maintenance minded and any brand name synthetic.


Honda's have mostly avoided the issues because the ownership base is one of the most adherent to maintenance recommendations including the maintenance minders.

"Enthusiast"-focused car brands have fared the worst.


That actually makes sense. Hmm. I think I'm going to stick with the Maintenance Minder. I was even feeling guilty about following the every other filter change like they say. Any opinion on that?


Inadequate oil quantity is the biggest enemy of K24 engines insofar as oil is concerned. There has yet to be, in the UOA section, a UOA posted from a K24 anywhere even remotely near condemnation limits.
 
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