50K+ Mile Owners - Intake Carbon Buildup

Anchorman said:

Another pointless thread based on the subjective opinion of somebody that thinks he can hear and feel the difference of things like different oil viscosity, different fuel grades and even the effects of redlining an engine has on valve cleanliness. GJ, stop it, you're like Walter Mitty. You occasionally make some sense and then you just go and undo it all again with these daft comments.

There is no evidence that occasionally redlining your engine will clean your valves. It probably won't damage your engine but it will just waste a lot of fuel.

You can't tell the difference under normal driving conditions between using different grade fuel and you can't hear the difference between which of the allowed oil viscosities are inside an engine. It's your imagination playing games.

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Redlining the engine stretches the connecting rods EVER so slightly. Not so much today, but "back in the day", if an engine was always driven at 3000rpm max (for example), and then one day you goosed it up to 5500rpm, you would possibly break the rings, as they had formed ridges in the cylinder wall at the lower rpm/amount of rod stretch. Today, cylinder liners are a thing, and so forth, but I still think it's healthy to run the engine/trans through the rpm band on occassion.

Unobtanium said:

Redlining the engine stretches the connecting rods EVER so slightly. Not so much today, but "back in the day", if an engine was always driven at 3000rpm max (for example), and then one day you goosed it up to 5500rpm, you would possibly break the rings, as they had formed ridges in the cylinder wall at the lower rpm/amount of rod stretch. Today, cylinder liners are a thing, and so forth, but I still think it's healthy to run the engine/trans through the rpm band on occassion.

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I would say that on occasions it doesn't harm but there is no evidence to say it is healthy. I would want the opinion of an engine test technician/ development engineer.

finch204 said:

From what I remember, the general consensus from the Mazdaspeed community is that Seafoam doesn't really do anything to combat the build-up on the MZR direct injection engines. The recommended course of action is to walnut blast the valves every 30k miles or so. So I don't know if it will do any better with the newer direct injection SkyActiv engines. I for one am not going to try it on our CX-5. I'll have the valves cleaned at the 60k mile mark.

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Coming from an engineering/science background and having been on forums since the late 90s for different car marques, I put little faith on what anybody said on the forum that relates to engineering/science results. Even here. I have seen way way way too many "forum experts" who talk a good talk, but have no real data to back it up. The cold and hot compression test data screenshot from the video I shared above show a crystal clear concrete difference and improvement.

Speedie95 said:

http://www.motoiq.com/MagazineArtic...l-introducing-mazdas-skyactiv-technology.aspx

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Speaking of "forum experts", I put complete faith on Mike Kojima, the writer of that article and founder of MotoIQ. Kojima cuts through forum bs with real data and applied knowledge for years. He also has friends within Nissan and and Mazda (both have design offices in Southern California, where he lives) and gets information from the source. I first followed Kojima back in the late 90s when I had my Nissan and have met him countless times over the years at several different race tracks in California (when I lived there). I would take anything he says with a LOT of weight.

That was great information Speedie95. Thank you for sharing it. These newer DI engines "should" have less of a problem with valve buildup.

Aviboy97 said:

Higher octane fuel does not burn cleaner. There is no potential for more power with higher octane fuel unless the car was designed to run on it.

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This is absolutely true.

One BRAND may burn more cleanly than another, but there will be no difference burn cleanliness just based on octane level.

Let me explain why you may get "more hp" from higher octane.
To put it most simply, higher octane is only needed to prevent detonation.

Detonation is when the the explosion happens inside the combustion chamber before it's supposed to, before the spark from the spark plug actually ignites the mixture. Detonation is bad and on the extreme case, can blow up engines. Rotary engines are uniquely more sensitive to detonation damage than V or inline engines.

When different variables within an engine (fuel mixture, air temp, engine temp, etc.) change, they can cause detonation to occur. Besides fixing the root cause of the detonation (which can be laborous and expensive), the simple fix is to put higher octane gas in. When you are having detonation issues with it's factory recommended gas octane, you will have more horsepower with higher octane gas.

If the factory rated octane level is high, it's due to the engine design they came up with to create a higher horsepower.

Many people who tune cars, more so with forced induction cars, will create an engine situation that may cause it to detonate. They will avoid the detonation by putting higher octane gas inside.

Really good engine designs will create the same horsepower with lower octane.
Unfortunately, better designs usually require more expensive materials, more expensive complex builds, more weight, more expensive sensors, etc.. Many times, engineers haven't figured out how to improve the design to work with lower octane gas.

People buy cars on price and don't put as much value on octane requirements of the cars.
So higher hp engines traditionally will require higher octane.


I want to repeat an important point.
You will only get more horsepower from a car with higher octane if it already isn't running as well as it should with the recommended octane.

The probability of getting more horsepower with just octane from a brand new, good running engine is extremely extremely low and if it's a big enough increase, the engineers should be fired. They should be fired because they should have then marketed the car with a higher horsepower rating and a higher octane requirement.

You may also get it just because you are lucky enough that all the tolerances of the engine (including air temp/humitity/pressure) line up in a way like the planets all line up in the solar system, that you actually get more hp. This can happen too. This is also why you can't put too much value on dyno hp numbers with you add engine modification. We used to call high hp cars, dyno queens, because they can only get them on the dyno and not in the real world where air temp, humity, and pressure are always changing.

GJ-Molestor said:

Hey everyone, thought Id make an update. My dad went ahead and did an oil change today, he used liqui moly either 5w30 or 40 and The engine runs much, smoother and more quiet then it did before. The intake rumbling sound when shifting into second gear was very loud and made the engine feel laggy and completely clogged with carbon. As soon as the oil was changed, the sound is 99% gone and the engine runs so much smoother then before.

So on top of what weve been discussing (avoid short trips and city driving, do occasional full throttle pulls) oil change frequency and the type of oil used is very important as well. I recommend changing the oil every 5000miles.

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1. Anybody who's Dad changes the oil in their own personal car, I would take their mechanical opinions and conclusions with a grain of salt. I don't mean this as a jab at you. I can see where the comment can be seen as that. I appoligize if it does.

2. In over 25yrs of changing the oil, the car ALWAYS has run better for me and it always will, unless you change it way too early.

3. Changing your oil has nothing to do with clearing any carbon buildup.

leedar said:

Coming from an engineering/science background and having been on forums since the late 90s for different car marques, I put little faith on what anybody said on the forum that relates to engineering/science results. Even here. I have seen way way way too many "forum experts" who talk a good talk, but have no real data to back it up. The cold and hot compression test data screenshot from the video I shared above show a crystal clear concrete difference and improvement.

Click to expand...

I'm just sharing what I have read from spending time on the Mazdaspeed forums. Maybe Seafoam works on most other cars, but the consensus is that it doesn't work well on the Mazdaspeed engines. If you have time, check out the links below. Note that no one that has tried using Seafoam on their Mazdaspeed engines, are actually recommending it based on the threads linked below. On that third link, there is even a note that after 5 years since that post was made, OP is not recommending Seafoam on the Mazdaspeed engines.

http://**************************/forum/f505/seafoam-not-seafoam-113688/
http://**************************/forum/f544/seafoam-safe-175709/
http://**************************/forum/f128/how-seafoam-your-cx-7-a-63610/

Maybe Seafoam will work on the CX-5 engines. Maybe we won't need to do it at all because of the improved engine design. Either way, I'm not trying it out on our CX-5 and will just have the valves walnut blasted at 60k miles. If at 60k miles the valves are clean, then awesome. If they're not, then walnut blasting should clean it up again.

Edit: Looks like forums link don't work, most likely due to past history between this forum and that. If you want the full link to the threads, send me a message.

Anchorman said:

I would say that on occasions it doesn't harm but there is no evidence to say it is healthy. I would want the opinion of an engine test technician/ development engineer.

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No harm when done occasionally. I mention this because conservatively driven vehicles that dont occasionally see redline will have carbon, unburnt fuel and all sorts of s*** building up in the exhaust. You will smell it the first time you floor it after a while. Engine runs smoother when you clear it out. You know this is a real thing when you smell it less and less and by the fourth redline, the smell is completely gone.

leedar said:

1. Anybody who's Dad changes the oil in their own personal car, I would take their mechanical opinions and conclusions with a grain of salt. I don't mean this as a jab at you. I can see where the comment can be seen as that. I appoligize if it does.

2. In over 25yrs of changing the oil, the car ALWAYS has run better for me and it always will, unless you change it way too early.

3. Changing your oil has nothing to do with clearing any carbon buildup.

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Its my dads daily driver. My dad wouldnt be changing the oil on my car if it was my car. My daily driver is a 528i as noted in my signature.

Although this video is about the MX-5, I've set it at the point where the reviewer explains that Mazda isn't seeing a carbon build-up with their direct injection (2.0 & 2.5L) engines because they use an air/oil separator before the PCV valve: https://youtu.be/R7yHcGbBh7g?t=13m10s

Anchorman said:

I would say that on occasions it doesn't harm but there is no evidence to say it is healthy. I would want the opinion of an engine test technician/ development engineer.

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The system is designed to attain 6200rpm or whatever it is. I have found that if you never run something hard, it's just not as able, ultimately. Now I don't mean beat on it, flog it about, etc. I simply mean "operate it to the edge of its design parameter". It is not designed for SUSTAINED 6200 rpm, or 6200rpm 100x a day, so be sensible and use it how it was designed. (Marine and dirt-track motors are very very different, and are designed for constant high rpm operation, and it shows in the A/F ratios, etc. they are tuned for).

The question is...will it fail at 6201rpm? Do you think they somehow left NOTHING on the table? ZERO margin of error? Of course you don't think that. Noone is that stupid. So if we can agree that the engineers left something on the table, we can also agree that they left something SENSIBLE on table, and created a proper buffer zone, if you will. So why arbitrarily create your own, again, with a whopping "Well I think..." for your design engineering data of where your arbitrary "I will not take the engine past XXXX rpm..." decision?

That's my opinion on it, anyway, and I have only had one vehicle that died on me, engine-wise. It was a police interceptor P71 with 200+ thousand miles on it, and it drank oil, and I forgot to replace it and it seized on me. I had a Trans Am in college, and it saw redline daily, my G20 that I traded it for saw redline ALL THE TIME because it was so gutless, lol! Engines were all fine. I did a compression test on the G20 at 110k miles, and it blew within 5psi of "new" spec. It was 5psi high across the board, IIRC. At 149K when I sold it, it was still doing great...the transmission, not so much. Died like a dog after a fluid change.

Unobtanium said:

The system is designed to attain 6200rpm or whatever it is. I have found that if you never run something hard, it's just not as able, ultimately. Now I don't mean beat on it, flog it about, etc. I simply mean "operate it to the edge of its design parameter". It is not designed for SUSTAINED 6200 rpm, or 6200rpm 100x a day, so be sensible and use it how it was designed. (Marine and dirt-track motors are very very different, and are designed for constant high rpm operation, and it shows in the A/F ratios, etc. they are tuned for).

The question is...will it fail at 6201rpm? Do you think they somehow left NOTHING on the table? ZERO margin of error? Of course you don't think that. Noone is that stupid. So if we can agree that the engineers left something on the table, we can also agree that they left something SENSIBLE on table, and created a proper buffer zone, if you will. So why arbitrarily create your own, again, with a whopping "Well I think..." for your design engineering data of where your arbitrary "I will not take the engine past XXXX rpm..." decision?

That's my opinion on it, anyway, and I have only had one vehicle that died on me, engine-wise. It was a police interceptor P71 with 200+ thousand miles on it, and it drank oil, and I forgot to replace it and it seized on me. I had a Trans Am in college, and it saw redline daily, my G20 that I traded it for saw redline ALL THE TIME because it was so gutless, lol! Engines were all fine. I did a compression test on the G20 at 110k miles, and it blew within 5psi of "new" spec. It was 5psi high across the board, IIRC. At 149K when I sold it, it was still doing great...the transmission, not so much. Died like a dog after a fluid change.

Click to expand...

You seem to have missed the point in all your pontificating about revs. Nobody said that an engine wouldn’t stand revving to the red line or higher. What I said was that there is no proof that doing so is “healthy”. That comment suggest there is a benefit to revving to the red line and it is that I question.

finch204 said:

I'm just sharing what I have read from spending time on the Mazdaspeed forums. Maybe Seafoam works on most other cars, but the consensus is that it doesn't work well on the Mazdaspeed engines. If you have time, check out the links below. Note that no one that has tried using Seafoam on their Mazdaspeed engines, are actually recommending it based on the threads linked below. On that third link, there is even a note that after 5 years since that post was made, OP is not recommending Seafoam on the Mazdaspeed engines.

Click to expand...

finch204, thank you for sharing those details.

After reading your post, (yes, your links don't work) I did a search here.
I went to page 3 of that search and clicked on about 7 threads or so. The general concensus was that lots of people, especially Protoge owners, used Seafoam with success. Years of succcess and nobody had problems due to it, except one person had a bad O2 sensor (~100k mile car) immediately after it, but I predict that is more to do with it being marginal and Seafoam pushed it over the edge. 100k failure on an O2 sensor is fairly normal and not crazy. It may also have been there was so much crap and the sensor just needed cleaning to make it work again. I don't know as there's no additional details or photos.


I then realized you said Mazdaspeed forums, and I didn't search there, but here, which is a different forum.. (hand slap to forehead)
I did a search but I didn't find anything in the 5 threads I skimmed through. I've gotten tired and impatient now seeing so much bs and no meat on the forums.



Found the following video (on a Harley Davidson forum with the title, "Why you should NOT use Seafoam...")
that says Seafoam, although works a little, is not as good as regular fuel injector cleaner when you soak valves in the solutions at room temperature overnight.


My (not his) conclusion, in this unique testing situation,
both disolve remove material from the valves. His brand of fuel injector cleaner seems to do it better job than Seafoam in his test situation.


The following video is a better test as they use valves from two different engines and he takes them out of the solution to check them.
(note that these are all at room temperature and not heated to 195F.)
Here, unlike the above video, Seafoam is a darker color, but seems to not remove the material more than Berrymans B-12.
Here, he conclusively proves, you can't judge material removal based on delution color. This is absolutely true.


(ignore that his glove reacts to Barrymans B-12 because you don't know what material the glove is. Somebody confidently claimed thay are rubber, but if you watch the video, he doesn't say what material they are. Be cautious of assumptions. If you read the replies, you'll find their Nitrile and the solution is completely safe for the car.)


Again, these videos are not scientific and there are way too many unknown variables.

A proper test would be a much more controled and analyzed test.

A. Verify the condition of the test pieces.
.........a. Take a few samples of deposit.
..................1. What precise chemicals are found and at what amount. Create a chart like this telling you what materials are there.
...........................
.........b. Measure precise thickness of deposit and several points.
.........c. Measure the valve surfaces and material.
..................1. Is the valve plated with anything? If so, what?
..................2. What precise material is the valve made of?
..................3. Measure exactly how rough or smooth the surface finish is on the neck, top face, bottom face.
.........d. Take samples of the test solutions (seafoam, injector cleaner, or Barrymans B-12).
..................(Sometimes the chemistries change over time or the ratio of the chemicals within change over the years. You can't blindly assume for example, the Seafoam sold 5yrs ago is the EXACT SAME sold today)
..................1. Like the deposits, measure what precise chemicals are found and at what amount.
.........d. Measure air temp, solution temperature, and valve temperature.
B. Introduce solutions.

C. Verify the condition of the test pieces.
.........a. Take a few samples of deposit remaining.
..................1. What precise chemicals are found and at what amount.
.........b. Measure deposit thickness remaining at exact same points as before.
.........c. Measure chemistry of desolved material in chemical solution.


Even after this test, you still wouldn't have tested it at temperature with air blowing over it, with fuel, or the exact enviornment it's used.

Heating two different materials that are attached to each other, will cause them to change size at different rates and can help to separate them (depending on the materials).



My conclusion based on my research,

Barrymans B-12 before each 2nd oil change.
I plan to return my Seafoam to the store. I'm confident it helps, but I believe Barrymans B-12 does a better job.

I assume one would have to administer any of these cleaners upstream in the intake for them to be effective on a DI motor to touch the valves. Is that correct?

Kedis82ZE8 said:

I assume one would have to administer any of these cleaners upstream in the intake for them to be effective on a DI motor to touch the valves. Is that correct?

Click to expand...

Yes,
upstream of the intake valves and in such a manner to get full coverage across all valves and not just half or a corner of the engine.

leedar said:

Yes,
upstream of the intake valves and in such a manner to get full coverage across all valves and not just half or a corner of the engine.

Click to expand...

This is not the ideal method

GJ-Molestor said:

This is not the ideal method

Click to expand...

Please enlighten us on what is ideal then,please...

NelsonLewis said:

Please enlighten us on what is ideal then,please...

Click to expand...

taking off the intake manifold and either a walnut blasting or physically scrape all that s*** off.

but, it's not needed until very high mileage on these skyactiv motors, because Mazda has taken the necessary precautions with a special PCV system to ensure that these motors do not suffer from carbon build-up. I'm sure that some careful tinkering with the injection/ignition timing also helped.

leedar said:

finch204, thank you for sharing those details.

After reading your post, (yes, your links don't work) I did a search here.
I went to page 3 of that search and clicked on about 7 threads or so. The general concensus was that lots of people, especially Protoge owners, used Seafoam with success. Years of succcess and nobody had problems due to it, except one person had a bad O2 sensor (~100k mile car) immediately after it, but I predict that is more to do with it being marginal and Seafoam pushed it over the edge. 100k failure on an O2 sensor is fairly normal and not crazy. It may also have been there was so much crap and the sensor just needed cleaning to make it work again. I don't know as there's no additional details or photos.


I then realized you said Mazdaspeed forums, and I didn't search there, but here, which is a different forum.. (hand slap to forehead)
I did a search but I didn't find anything in the 5 threads I skimmed through. I've gotten tired and impatient now seeing so much bs and no meat on the forums.



Found the following video (on a Harley Davidson forum with the title, "Why you should NOT use Seafoam...")
that says Seafoam, although works a little, is not as good as regular fuel injector cleaner when you soak valves in the solutions at room temperature overnight.

My (not his) conclusion, in this unique testing situation,
both disolve remove material from the valves. His brand of fuel injector cleaner seems to do it better job than Seafoam in his test situation.


The following video is a better test as they use valves from two different engines and he takes them out of the solution to check them.
(note that these are all at room temperature and not heated to 195F.)
Here, unlike the above video, Seafoam is a darker color, but seems to not remove the material more than Berrymans B-12.
Here, he conclusively proves, you can't judge material removal based on delution color. This is absolutely true.

(ignore that his glove reacts to Barrymans B-12 because you don't know what material the glove is. Somebody confidently claimed thay are rubber, but if you watch the video, he doesn't say what material they are. Be cautious of assumptions. If you read the replies, you'll find their Nitrile and the solution is completely safe for the car.)


Again, these videos are not scientific and there are way too many unknown variables.

A proper test would be a much more controled and analyzed test.

A. Verify the condition of the test pieces.
.........a. Take a few samples of deposit.
..................1. What precise chemicals are found and at what amount. Create a chart like this telling you what materials are there.
...........................

.........b. Measure precise thickness of deposit and several points.
.........c. Measure the valve surfaces and material.
..................1. Is the valve plated with anything? If so, what?
..................2. What precise material is the valve made of?
..................3. Measure exactly how rough or smooth the surface finish is on the neck, top face, bottom face.
.........d. Take samples of the test solutions (seafoam, injector cleaner, or Barrymans B-12).
..................(Sometimes the chemistries change over time or the ratio of the chemicals within change over the years. You can't blindly assume for example, the Seafoam sold 5yrs ago is the EXACT SAME sold today)
..................1. Like the deposits, measure what precise chemicals are found and at what amount.
.........d. Measure air temp, solution temperature, and valve temperature.
B. Introduce solutions.

C. Verify the condition of the test pieces.
.........a. Take a few samples of deposit remaining.
..................1. What precise chemicals are found and at what amount.
.........b. Measure deposit thickness remaining at exact same points as before.
.........c. Measure chemistry of desolved material in chemical solution.


Even after this test, you still wouldn't have tested it at temperature with air blowing over it, with fuel, or the exact enviornment it's used.

Heating two different materials that are attached to each other, will cause them to change size at different rates and can help to separate them (depending on the materials).



My conclusion based on my research,

Barrymans B-12 before each 2nd oil change.
I plan to return my Seafoam to the store. I'm confident it helps, but I believe Barrymans B-12 does a better job.

Click to expand...

The regular search feature on Mazdaspeed forums doesn't work. You have to use google to search that forum a certain way to get back relevant results. Anyway I appreciate the info and research you have provided. I didn't know about that B-12 product until your post. If I remember correctly, the dealership I take my cars to, offers some fuel induction service/cleaners from MOC. I have not tried those on the CX-5 yet, because it still only has 23k miles.

GJ-Molestor said:

So what Ive gathered is that the more highway the better, and if you do frequent city driving at low rpm then 1 full throttle pull in second or third gear once a week (merging onto the highway for example) will help keep your motor clean.

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I'm sold on prolonged highway driving prevents carbon buildup, but I dont think the short rev-out will clean it out. It might do good for the injectors since they're opening fully and any carbon that builds on the tips, can be removed that way, but for extreme situations, they say running the car in 5th or 4th gear doing 60+ while it's revving at 3,000rpm+, and then setting the cruise, locking it into gear and driving for at least a half hour, will almost rid the engine of carbon buildup. Some techs do it at BMW, they just get on the highway, get into 4th and drive for about 30mins and come back, re-inspect and she's good to go with clean valves.

buyingconstant7 said:

I'm sold on prolonged highway driving prevents carbon buildup, but I dont think the short rev-out will clean it out. It might do good for the injectors since they're opening fully and any carbon that builds on the tips, can be removed that way, but for extreme situations, they say running the car in 5th or 4th gear doing 60+ while it's revving at 3,000rpm+, and then setting the cruise, locking it into gear and driving for at least a half hour, will almost rid the engine of carbon buildup. Some techs do it at BMW, they just get on the highway, get into 4th and drive for about 30mins and come back, re-inspect and she's good to go with clean valves.

Click to expand...

assuming that we are talking about an early model DI motor like a BMW 335i which did have carbon build-up issues: (unlike our skyactiv motors)

if you do not already have a layer of buildup on the valves, a full throttle pull roughly once a week will help keep your valves clean for longer VS a conservatively driven motor, but you are correct that an extended highway trip is in fact more effective. there are other more useful benefits to occaisonally WOT pulls such as cleaning out the injectors like you mentioned.

my dad drives conservatively for long periods of time. whenever I get the chance to take the car out for a spin, I do a full throttle pull to help clear things out and the exhaust smells absolutely awful for 2-3 pulls and then you smell nothing. I understand that this smell has little to do with carbon. so I assume that I am cleaning out the injectors when I do this? is there anything else in the motor that will benefit from an occasional pull?