Preventing sludge/varnish with Honda J35A7 VCM enabled engines.

B

Bill7

Joined
Nov 30, 2013
Messages
1,203
Location
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For anyone familiar with the 2005-2007 Honda Odyssey J35A7 engines which have VCM enabled,
they have some design flaws with a poorly designed PCV system, and have extreme heat on the front cylinder heads which cook the oil.
This issue mainly affects 2005-2007 Honda Odysseys with VCM version 1 enabled, not the 2008+ Honda V-6'ss with the VCM version 2.

Because of these design flaws short oil change intervals were recommended by some subject matter experts on the forum to avoid sludge/varnish buildup.

I'm not interested in disabling the VCM as I prefer to get the 1 to 2 MPG improvement with VCM, so please don't suggest a VCM muzzler.

To try to prevent the sludge/varnish issues caused by the extreme heat in certain parts of the engine,
I'm avoiding conventional oils, 20 weight oils, and the maintenance minder (as many who follow the maintenance minder get the sludge/varnish).

I've been doing 4k/6 month OCI's, which in this day and age for modern vehicles is unheard of (Most automakers recommend 10k/1 year OCI). But still, for these 2005-2007 VCM version 1 engines, the extreme heat on the front cylinder heads + poorly designed PCV require the short OCI.

Driving is with the eco light on 90% of the time, as my family drives with a light foot and typically sets the cruise control
to whatever the speed limit is (55 MPH or 65 MPH). 3 Vehicles are driven 35 miles twice a day on the highway, and one vehicle is driven 11 miles twice a day with cruise control set at either 45 MPH or 55 MPH. Vehicles do short trips on the weekends too, and where I live the temperature is from 0 to 32F December through March.

The question I'm hoping the SME's and mechanic's who have experience with these engines on BITOG is:

If I move from 4k/6 month to 5k/6 month OCI with a 5W-30 Full Synthetic Dexos 1 Gen 3 approved low Noack oil
with Noack varnish over the next 100,000 miles.

Across the four 2006/2007 Honda Odyssey's with VCM enabled driving 15k, 15k, 15k, 7k miles respectively, I could save $500 total over the next 5 years by switching from 4k to 5k OCI's, but I would only want to do it if there wouldn't be any new sludge/varnish added to the engine. Despite the vehicles' age, I want to keep all 4 vehicles for 10+ more years.
 
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BMWTurboDzl said:
Unknown but Mobil 1 0w40 is your answer.
Click to expand...
Good suggestion. Mobil 1 0W-40 has some good cleaning abilities and low Noack.

The idea behind the $500 total savings on oil changes over 5 years was to use a low priced full synthetic Dexos 1 Gen 3 oil with low Noack 6 month OCI would not add any sludge / varnish to the engine over the next 100,000 miles.

For most vehicles, the 5k / 6 month OCI would not cause any significant sludge/varnish.
But the 2005 to 2007 Honda Odysseys with VCM enabled could be an exception due to the high heat on front cylinder heads and poorly designed PCV.
 
Bill7 said:
Good suggestion. Mobil 1 0W-40 has some good cleaning abilities and low Noack.
Click to expand...
I don't think any 0W40 will have a "low" NOACK due to the VI Improver that is needed to achieve such a wide viscosity range. M1 0W40 is approved for MB 229.5 so the NOACK has to be 10% or less. But I am willing to bet that it is very very close to the 10% mark.

However, if we want to get super picky, there are plenty of boutique 5W20 and 5W30 oils with a NOACK below 7%.
 
The Critic said:
I don't think any 0W40 will have a "low" NOACK due to the VI Improver that is needed to achieve such a wide viscosity range. M1 0W40 is approved for MB 229.5 so the NOACK has to be 10% or less. But I am willing to bet that it is very very close to the 10% mark.

However, if we want to get super picky, there are plenty of boutique 5W20 and 5W30 oils with a NOACK below 7%.
Click to expand...
Last time I checked it was 8.7%.

Also, Noack is being revised as it doesn't correlate to oil consumption.

Modifications to the Noack volatility test, which determines the evaporative loss of engine oils related to evaporative oil consumption, may be required. Recent research has indicated that standard Noack tests do not correlate well with actual engine oil consumption. Deegan detailed a change to the temperature in the volatility test from 250°C to 150°C for an improved engine to bench correlation. SAE Paper 2022-01-05241 has previously demonstrated a good correlation with evaporative oil consumption in actual engine operation with a modified Noack test at 150°C."
 
The Critic said:
I don't think any 0W40 will have a "low" NOACK due to the VI Improver that is needed to achieve such a wide viscosity range. M1 0W40 is approved for MB 229.5 so the NOACK has to be 10% or less. But I am willing to bet that it is very very close to the 10% mark.

However, if we want to get super picky, there are plenty of boutique 5W20 and 5W30 oils with a NOACK below 7%.
Click to expand...
It it correct to say that a lower 12.5% Noack oil will form less sludge and varnish than a 15% Noack oil.
 
The Critic said:
Not necessarily. I have not seen any publications confirming that NOACK is the primary driver of sludge and varnish deposits.
Click to expand...
Lower Noack means lower evaporative loss at extremely high temperatures.

I took this to mean lower Noack oil's would better withstand high heat situations with less deposits that can cause varnish and possibly sludge. Please correct me if I am incorrect.
 
From SonofJoe:

"In itself, the Noack volatility is a meaningless number. The test measures how much oil, when held at 250°C, evaporates into a stream of cold air over the course of one hour. The reality is that your oil (typically at 100°C) might be exposed to a stream of hot blow-by for 300 hours. How much oil exits the crankcase with blow-by in this situation? The answer depends on a whole host of variables? Do you drive modestly (like me) or in a spirited fashion (everyone else on BITOG)? Do you live in a non-extreme climate (like me) or do you live in a country that sees extremes of hot and cold? Do your engine see significant fuel dilution (from low tension rings, or because it's TGDI, or because you live in a cold climate?). Is your engine nice a tight (because it's relatively new) or worn out and letting through a lot of blow-by? Do you have a typical OCI of 3k miles or 15k? I once ran an 11%-ish Noack oil of my own making and lost 40% of it over 15,000 miles!"

"This is the way this works... From a base oil point of view, Di-esters usually give you the lowest Noack followed by PAO, followed by GTL, followed by normal Group IIIs. These are followed by Group I & II base oils, which can vary a lot depending on source, but should be treated as roughly equivalent and the worst. VII polymer type & SSI will impact on Noack. For a given viscometric balance, a 5W20 based on Hydrogenated Styrene-Diene (HSD) VII will have a lower Noack than one based on cheaper, commoner Olefin Copolymer (OCP) VII. Likewise, an oil based on high SSI (ie more shearable) VII will give you a lower Noack than the same VII with a lower SSI (typically used in European oils). Oils that contain a lot of DI additive will have a higher Noack than ones that contain less DI. Typically, European PCMOs (which are formulated to handle both gasoline & diesel) have higher DI treats and directional have higher Noacks than say US gasoline-only PCMOs. Finally (and this is a biggie so pay attention!) whether a 5W20 is blended viscometrically 'tight' or 'slack' has a HUGE impact on its Noack. At the extreme, a tight 5W20 will have a KV100 of 6.91 cst and a CCS-30 of 6,599 cP. At the other end of the scale, a 'slack' 5W20 might have a KV100 of 9.29 cst and a CCS-30 of say 3,301 cP (if it goes much lower, it risks becoming a 0W20). Both of these oils are valid 5W20s yet the latter slack oil will have a much higher Noack than the tight oil. US ILSAC oils tend to be slacker than the equivalent API oil. Euro oils tend to be tight in general. So in summary, for the lowest practical Noack, you want a 5W20 blended with a mix of Di-ester & PAO, formulated with a high SSI HSD VII and a low DI treat Add Pack (say SL) that's blended tight by someone who understands how to do these things properly (like me!). Failing that, look for 5W20 oils from Redline or Amsoil. Having said all that, I personally wouldn't obsess about using the absolutely lowest Noack 5W20 oil I could get my hands on. My primary beef about Noack is that in the US, you can still find oils with close to the 15% Noack limit. This is TOO HIGH!! A more sensible limit is 13% max as this forces out the most volatile light base oils which do so much damage to oil control rings. A better limit, if you intend to keep your car going for decades might be 10% max. Beyond 10% then benefits of lower Noack I'd judge to be marginal and probably not worth the on-cost. The way to philosophically rationalise this is that Noack-wise, life is not about coming first; it's about not coming last..."

Also consider this: (NOT SonofJoe)

"So, there is more of a reverse correlation between the TEOST 33C deposits test and NOACK volatility -- the higher the NOACK volatility, the thinner the base oil is and therefore the more the solvency it has and the more the deposits it can dissolve and remove. And, perhaps, a faster-evaporating oil has less time to leave deposits behind. Of course, the base-oil type plays a crucial type. There is no comparison between Group III and Group II. So, don't compare apples to oranges. Higher NOACK causing less deposits only applies within the same base-oil type. A PAO or a GTL will have less deposits than a Group II no matter what the NOACK is. That's why the PAO-based Amsoil SS did so well in both tests. The additive package also plays a crucial role. The #1-ranked Castrol has a so - so Group III base oil but it did so well probably partially due to its additive package. http://amsoil.com/lit/g3115.pdf The moral of the story: Don't base your oil selection solely on NOACK, with the hope that it will clean better etc."
 
Last edited:
In regard to your post about varnish - HPL, Amsoil have very good solvency.
 
Bill7 said:
I took this to mean lower Noack oil's would better withstand high heat situations with less deposits that can cause varnish and possibly sludge. Please correct me if I am incorrect.
Click to expand...
Short answer, not exactly. Buster's post explains it in more detail.
 
buster said:
From SonofJoe:

"In itself, the Noack volatility is a meaningless number. The test measures how much oil, when held at 250°C, evaporates into a stream of cold air over the course of one hour. The reality is that your oil (typically at 100°C) might be exposed to a stream of hot blow-by for 300 hours. How much oil exits the crankcase with blow-by in this situation? The answer depends on a whole host of variables? Do you drive modestly (like me) or in a spirited fashion (everyone else on BITOG)? Do you live in a non-extreme climate (like me) or do you live in a country that sees extremes of hot and cold? Do your engine see significant fuel dilution (from low tension rings, or because it's TGDI, or because you live in a cold climate?). Is your engine nice a tight (because it's relatively new) or worn out and letting through a lot of blow-by? Do you have a typical OCI of 3k miles or 15k? I once ran an 11%-ish Noack oil of my own making and lost 40% of it over 15,000 miles!"

"This is the way this works... From a base oil point of view, Di-esters usually give you the lowest Noack followed by PAO, followed by GTL, followed by normal Group IIIs. These are followed by Group I & II base oils, which can vary a lot depending on source, but should be treated as roughly equivalent and the worst. VII polymer type & SSI will impact on Noack. For a given viscometric balance, a 5W20 based on Hydrogenated Styrene-Diene (HSD) VII will have a lower Noack than one based on cheaper, commoner Olefin Copolymer (OCP) VII. Likewise, an oil based on high SSI (ie more shearable) VII will give you a lower Noack than the same VII with a lower SSI (typically used in European oils). Oils that contain a lot of DI additive will have a higher Noack than ones that contain less DI. Typically, European PCMOs (which are formulated to handle both gasoline & diesel) have higher DI treats and directional have higher Noacks than say US gasoline-only PCMOs. Finally (and this is a biggie so pay attention!) whether a 5W20 is blended viscometrically 'tight' or 'slack' has a HUGE impact on its Noack. At the extreme, a tight 5W20 will have a KV100 of 6.91 cst and a CCS-30 of 6,599 cP. At the other end of the scale, a 'slack' 5W20 might have a KV100 of 9.29 cst and a CCS-30 of say 3,301 cP (if it goes much lower, it risks becoming a 0W20). Both of these oils are valid 5W20s yet the latter slack oil will have a much higher Noack than the tight oil. US ILSAC oils tend to be slacker than the equivalent API oil. Euro oils tend to be tight in general. So in summary, for the lowest practical Noack, you want a 5W20 blended with a mix of Di-ester & PAO, formulated with a high SSI HSD VII and a low DI treat Add Pack (say SL) that's blended tight by someone who understands how to do these things properly (like me!). Failing that, look for 5W20 oils from Redline or Amsoil. Having said all that, I personally wouldn't obsess about using the absolutely lowest Noack 5W20 oil I could get my hands on. My primary beef about Noack is that in the US, you can still find oils with close to the 15% Noack limit. This is TOO HIGH!! A more sensible limit is 13% max as this forces out the most volatile light base oils which do so much damage to oil control rings. A better limit, if you intend to keep your car going for decades might be 10% max. Beyond 10% then benefits of lower Noack I'd judge to be marginal and probably not worth the on-cost. The way to philosophically rationalise this is that Noack-wise, life is not about coming first; it's about not coming last..."

Also consider this: (NOT SonofJoe)

"So, there is more of a reverse correlation between the TEOST 33C deposits test and NOACK volatility -- the higher the NOACK volatility, the thinner the base oil is and therefore the more the solvency it has and the more the deposits it can dissolve and remove. And, perhaps, a faster-evaporating oil has less time to leave deposits behind. Of course, the base-oil type plays a crucial type. There is no comparison between Group III and Group II. So, don't compare apples to oranges. Higher NOACK causing less deposits only applies within the same base-oil type. A PAO or a GTL will have less deposits than a Group II no matter what the NOACK is. That's why the PAO-based Amsoil SS did so well in both tests. The additive package also plays a crucial role. The #1-ranked Castrol has a so - so Group III base oil but it did so well probably partially due to its additive package. http://amsoil.com/lit/g3115.pdf The moral of the story: Don't base your oil selection solely on NOACK, with the hope that it will clean better etc."
Click to expand...
Thank you for the very informative post. It makes a lot of sense.
 
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