Oil Strategy To Prevent Carbon Piston / Ring Deposits ?

[CANADADIY]

Good luck with that

Thanks, it was easy.

I have 2 in the driveway. One is 4 months old, one is 16 years old. I quite like them.

 

[Bryanccfshr]

I would say use VRP at manufacturer recommended intervals and top tier fuel. Its so simple.

 

[TiGeo]

Step 1. Don’t buy trash direct injection gasoline engines.

It's also part of why we can get crazy power out of small displacement turbo engines now so it's a double-edged sword. IVD is the main issue but even that is quite the internet boogie man now..I mean this stuff is like 15 years old/mature tech at this point. Only on BITOG is this drama...

 

[oil pan 4]

It can certainly happen from neglect, but I wouldn't classify that as the main mechanism.

You are familiar with Sequence IIIH, and its predecessor IIIG, correct?

Yeah. Run the engines, take them apart, look at the pistons.

 

[ClutchDisc]

Good luck with that

Easy. Have never owned a direct injection engine before and plan to keep it that way.

 

[OVERKILL]

Yeah. Run the engines, take them apart, look at the pistons.

Kind of. It's designed to expedite the aging of the oil, by running it at a higher temperature (150C, the temperature we run HTHS at), but the application (Chrysler Pentastar) is naturally aspirated and port injected, so not the most demanding. The test is designed to measure the oil's propensity to create piston deposits (and the conditions encourage them). The previous version, IIIG was effectively the same test, but run with a GM 3.8L engine.

The test lasts 90 hours, run at 3,600rpm at about 45% full power (137hp). We could use the hours to rough-out a mileage equivalent estimate (eg, 5,000 miles at an average speed of 55mph), but we might be best comparing it to something like towing, driving up oil temp and moderately increased load.

This was a pass with IIIG:

This is a pass with IIIH:

Now, I'm sure we can agree that 90 hours (5,000 miles of towing at 55mph?) isn't a long/extended OCI.

This is what @buster shared from AMSOIL:

Which I think does a good job illustrating how a higher quality oil can make a considerable difference here. AMSOIL at 180 hours (twice the drain interval) is still significantly cleaner than our "reference oil", or the "pass" above.

In the past, both Mobil and Pennzoil have posted IIIG pictures to show how much better than a "pass" their oils do in this sequence. Of course Valvoline is also using a variation of this same sequence to show how R&P is able to remove deposits.

So, @Patman noted, oil selection clearly plays a role. There is a considerable difference between an oil that just passes the test and one that massively out-performs the requirements.

However, as I said, the Pentastar isn't a challenging application. Dealerships aren't pulling them apart due to oil consumption. A more representative example would be a low displacement TGDI mill with a baby sump, ones where we've seen cases of oil consumption.

The piston you shared showed generous land area, somewhat similar to the Pentastar and GM 3.8L pistons. I doubt it regularly saw 150C oil temps, am I right?

Look at how narrow the oil control land (with a stuck ring) is on this Toyota piston in comparison:

Now add a turbo and DI washing the bores down with fuel, torpedoing the oil film's volatility resistance.

So yes, engine design also plays a considerable role.

There are applications, like the Toyota 2.5, and the Honda 3.5L VCM engine that no matter how frequently you change the oil, the pistons rings cake up with deposits and oil burning starts, underscoring that short-changing is not some universal panacea. This is not neglect or abuse, it's engineering choices manifest, coupled with the unwillingness to address this through a specification or approval. Highlighting that further: this same trend has been mitigated, in many instances, by the use of better oils, like M1 0W-40 in the aforementioned Honda mills.

And yes, of course, if oil is left in service beyond the point where it's DI package is able to do its job, you will also get deposits (your neglect/abuse argument). But, depending on the application, the point at which that takes place will vary wildly.

So short changing Supertech for example, in an application that isn't easy on oil, can result in more deposits than longer drains on Mobil 1 or AMSOIL.

And yes, choice of lubricant can absolutely dictate whether you get ring coking or not, regardless of the OCI length. And this is dictated by the mechanical and operational characteristics of the engine. An application that is harder on oil may require a better lubricant.

Also worth mentioning:

Thinner oils are allowed more deposits. For SQ, xW-20 and above must be 4.6 merits or above. 0W-16 is 4.2, 0W-8/0W-12? 3.7.

 

[danstraylee]

Just around timing belt change and valve inspection I had my 3.6 Honda bore scoped and it was pristine. What was strange is the fact that the "deactivation" rear bank looked pretty much like the front bank of cylinders. I do 3K-5K oil (0W-20) changes and use 91 Chevron/Shell almost exclusively. The tech that scoped it said he has never seen a direct injected motor with so little carbon buildup. Did not even need a walnut blast.

My engine has zero fuel dilution or oil consumption between oil changes. 5.6 quarts go in and 5.6 quarts come out. Unfortunately the front hydraulic motor mount was slightly wet indicating a leak. I recommend having it done unless you have a lift. I had a rough go of it installing it myself in driveway.

 

[rstsco]

How do you know what prevents piston ring deposits after all of 22k miles? Have you inspected the rings?

Of course not, but I have inspected every oil filter after each OCI. When running Shell premium, no appreciable carbon deposits are seen in the oil filter media. When I ran 87-octane, Top Tier certified gasoline from Quik Trip, there were quite a bit of carbon deposits in the oil filter media. Does this translate to carbon deposits in the piston ring grooves, I can not definitively say, but worth my running Shell premium without the carbon deposits in the oil filter media vs finding out the hard way.

 

[Big O Dave]

I use Shell or Chevron premium in my LSY-equipped Cadillac XT5. This car is spec’d for premium fuel and I consistently get 28 mpg with it, so it hurts a bit less when I have to pay for the fuel.

Having said that, my understanding of the benefit of using Top Tier Fuel in a TGDI engine (from a cleanliness point of view) is primarily keeping the fuel injectors clean and spraying the proper pattern in the combustion chamber which promotes cleaner combustion and less carbon buildup in the combustion chambers.

I also use a bottle of PEA at the end of each OCI as added assurance for my OCD.

I don’t think it can have much effect on carbon buildup on the intake valves.

I suspect that using low volatility oil to limit oil vapor in the PCV system contributes greatly to less buildup on the intake valves. It also would not surprise me at all if we found that the oil vapor when using VRP had a cleaning effect on these valves. Time will tell.

As an aside, I am loving this XT5 so far! It’s very comfortable and quiet, rides great since I had Michelin Defender 2’s installed and it is surprisingly entertaining to drive spiritedly on a curvy canyon road. Hopefully, this feeling continues well into the future!

 

[Azimuth]

Which I think does a good job illustrating how a higher quality oil can make a considerable difference here. AMSOIL at 180 hours (twice the drain interval) is still significantly cleaner than our "reference oil", or the "pass" above.

Isn't this showing that running AMSOIL for 2x the test duration starting to develop minor deposits, but runs clean at the original test duration - so the best option would be to use an oil like AMSOIL but *not* extend OCIs?

 

[TrialKid]

• Good base oils—GTL / PAO / Esters
• Relatively high viscosities—30-40 grade with Euro car approvals
• 5,000 to 7,500 miles oil change intervals (depending on engine type, driving style and conditions)

GTL is better on deposits ?, think of use SHELL Helix 5/40

 

[buster]

Isn't this showing that running AMSOIL for 2x the test duration starting to develop minor deposits, but runs clean at the original test duration - so the best option would be to use an oil like AMSOIL but *not* extend OCIs?

I wouldn't over think this. All you really need to know the oil is subjected to 304F for 90 hours. It's not meant to test anything other than how well the oil handles heat for a duration of time.

What Amsoil is demonstrating in this test is how thermally stable the oil is under heat for long durations of time. If the lab that tested it said they never saw an oil score higher, I'd feel comfortable saying Amsoil is among the most stable, heat-resistant oils you can buy right now.

Here is an article from the prior Amsoil run:

https://blog.amsoil.com/amsoil-crushes-sequence-iiih-engine-test/

5x higher load than typical highway driving.

 

[Faawrenchbndr]

Easy. Have never owned a direct injection engine before and plan to keep it that way.

Ok…….all I am say is it is the future of the ICE

 

[buster]

Summary:
oil is held at 304F for 90hrs
5.48x typical highway load on engine
special crappy fuel is added to the test to make it harder

That's pretty much it.

 

[buster]

*delete

 

[4wd]

*delete

Yes, delete the CBU

 

[4wd]

Summary:
oil is held at 304F for 90hrs
5.48x typical highway load on engine
special crappy fuel is added to the test to make it harder

That's pretty much it.

View attachment 348823

Do they take crappy fuel donations? You see, LSS - got this old boat …

 

[SC Maintenance]

Having over 400K miles on my Xterra all on conventional or blend, with no oil usage at all, I have concluded it’s mostly engine design.

Having said that I have decided to run low SAPS euro oil in everything else including my Toyota going forward. Whether that helps or not

 

[buster]

Kind of. It's designed to expedite the aging of the oil, by running it at a higher temperature (150C, the temperature we run HTHS at), but the application (Chrysler Pentastar) is naturally aspirated and port injected, so not the most demanding. The test is designed to measure the oil's propensity to create piston deposits (and the conditions encourage them). The previous version, IIIG was effectively the same test, but run with a GM 3.8L engine.

The test lasts 90 hours, run at 3,600rpm at about 45% full power (137hp). We could use the hours to rough-out a mileage equivalent estimate (eg, 5,000 miles at an average speed of 55mph), but we might be best comparing it to something like towing, driving up oil temp and moderately increased load.

This was a pass with IIIG:
View attachment 348776

This is a pass with IIIH:
View attachment 348775

Now, I'm sure we can agree that 90 hours (5,000 miles of towing at 55mph?) isn't a long/extended OCI.

This is what @buster shared from AMSOIL:
View attachment 348777

Which I think does a good job illustrating how a higher quality oil can make a considerable difference here. AMSOIL at 180 hours (twice the drain interval) is still significantly cleaner than our "reference oil", or the "pass" above.

In the past, both Mobil and Pennzoil have posted IIIG pictures to show how much better than a "pass" their oils do in this sequence. Of course Valvoline is also using a variation of this same sequence to show how R&P is able to remove deposits.

So, @Patman noted, oil selection clearly plays a role. There is a considerable difference between an oil that just passes the test and one that massively out-performs the requirements.

However, as I said, the Pentastar isn't a challenging application. Dealerships aren't pulling them apart due to oil consumption. A more representative example would be a low displacement TGDI mill with a baby sump, ones where we've seen cases of oil consumption.

The piston you shared showed generous land area, somewhat similar to the Pentastar and GM 3.8L pistons. I doubt it regularly saw 150C oil temps, am I right?

Look at how narrow the oil control land (with a stuck ring) is on this Toyota piston in comparison:
View attachment 348781

Now add a turbo and DI washing the bores down with fuel, torpedoing the oil film's volatility resistance.

So yes, engine design also plays a considerable role.

There are applications, like the Toyota 2.5, and the Honda 3.5L VCM engine that no matter how frequently you change the oil, the pistons rings cake up with deposits and oil burning starts, underscoring that short-changing is not some universal panacea. This is not neglect or abuse, it's engineering choices manifest, coupled with the unwillingness to address this through a specification or approval. Highlighting that further: this same trend has been mitigated, in many instances, by the use of better oils, like M1 0W-40 in the aforementioned Honda mills.

And yes, of course, if oil is left in service beyond the point where it's DI package is able to do its job, you will also get deposits (your neglect/abuse argument). But, depending on the application, the point at which that takes place will vary wildly.

So short changing Supertech for example, in an application that isn't easy on oil, can result in more deposits than longer drains on Mobil 1 or AMSOIL.

And yes, choice of lubricant can absolutely dictate whether you get ring coking or not, regardless of the OCI length. And this is dictated by the mechanical and operational characteristics of the engine. An application that is harder on oil may require a better lubricant.

Also worth mentioning:

Thinner oils are allowed more deposits. For SQ, xW-20 and above must be 4.6 merits or above. 0W-16 is 4.2, 0W-8/0W-12? 3.7.

So true. Those engines are tough on oil. Actually they'd be interesting candidates to test oils in.

I don't know how I feel now that I know most oils barely pass the IIIH according to Amsoil.

In that EE video there are some piston photos but they don't specifically show a Mobil 1 piston. For off the shelf I think Mobil 1 would likely do the best in the IIIH.

My thinking for VRP is it will leave deposits when pushed super hard, but will also actively clean once temps fall back down. So theoretically you could run VRP in a IIIH and come out with dirtier pistons than Amsoil. However, once temperatures fall back down to normal levels, VRP would clean them up. Or VRP is so good it won't leave any deposits but it will eventually break at some point and I think the IIIH would break it.

In other words, the SWRI lab basically gave credibility that Amsoil does make the most thermally stable oil.

 

[4wd]

Having over 400K miles on my Xterra all on conventional or blend, with no oil usage at all, I have concluded it’s mostly engine design.

Having said that I have decided to run low SAPS euro oil in everything else including my Toyota going forward. Whether that helps or not

Yep, many observers could “name that mill” (or makes) …
Have said before - go look at used 2500 cargo vans (6.0) on CarGurus.
Doubt most Plumbers are doing top shelf lubes …