50K+ Mile Owners - Intake Carbon Buildup

Wait - are there reports of carbon buildup on these engines? Lots of noise, little data.

Its a new direct injection motor... the amount of people experiencing carbon buildup so far is tiny and the amount of people that are active on a forum to share about this issue is even tinier. All the symptoms point at carbon buildup and the intake related code basically seals the deal for me...

Its a first generation, and mazdas first attempt at making a mainstream motor with direct injection (other then the 2.3L MZR from the past) so ignition/fuel timing is obviously not perfect yet.

Then again, people who regularly rev out the engine dont seem to have any problem with this even at high mileage, so I think it isnt much of a problem unless you dont rev the car hard ever.
 
Our cx5 2.5 has 55k and I swear it runs better than new. I attribute that to long highway driving. If you have a GDI engine and maybe once a month or two months do an hour or more of highway driving of +50mph, you should never have an issue of carbon buildup. In fact, my friends 2007 Passat 2.0TFSI did 5k a year for 5 years. He had rough running, cold start misfires, poor performance and mpg. He drove it across the country and back in a week and his engine light went off, and everything was restored back to how he remembered it when he drove it off the dealer lot. He now does about 1.5 hours of cruising each month in the mountains. That was 5 years ago and hes never had an issue since. I want to remove the cx5s intake manifold to see what the valve situation is like because at 55k, nothing is suffering and we do tons of road trips with this car.
 
Our cx5 2.5 has 55k and I swear it runs better than new. I attribute that to long highway driving. If you have a GDI engine and maybe once a month or two months do an hour or more of highway driving of +50mph, you should never have an issue of carbon buildup. In fact, my friends 2007 Passat 2.0TFSI did 5k a year for 5 years. He had rough running, cold start misfires, poor performance and mpg. He drove it across the country and back in a week and his engine light went off, and everything was restored back to how he remembered it when he drove it off the dealer lot. He now does about 1.5 hours of cruising each month in the mountains. That was 5 years ago and he’s never had an issue since. I want to remove the cx5’s intake manifold to see what the valve situation is like because at 55k, nothing is suffering and we do tons of road trips with this car.
Take some pictures of the valves too, if you do get to remove the intake manifold.
 
Our cx5 2.5 has 55k and I swear it runs better than new. I attribute that to long highway driving. If you have a GDI engine and maybe once a month or two months do an hour or more of highway driving of +50mph, you should never have an issue of carbon buildup. In fact, my friends 2007 Passat 2.0TFSI did 5k a year for 5 years. He had rough running, cold start misfires, poor performance and mpg. He drove it across the country and back in a week and his engine light went off, and everything was restored back to how he remembered it when he drove it off the dealer lot. He now does about 1.5 hours of cruising each month in the mountains. That was 5 years ago and hes never had an issue since. I want to remove the cx5s intake manifold to see what the valve situation is like because at 55k, nothing is suffering and we do tons of road trips with this car.

Its funny you mention that, because I was driving the car last night on the highway and noticed that it does indeed help.

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.

My dad daily drives the car which is why its even having this issue so early, so conservative drivers out there (which likely wont be on this forum) beware as these two points I mention are critical for avoiding carbon buildup in your motor.
 
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I read somewhere that DI engine's carbon build up cannot be cleaned by revving it up to the redline.

If there is already a noticeable layer of buildup on the valves then correct, redlines will not remove it.

The trick is to regularly do full throttle pulls and highway driving while the valves are still clean and avoid any buildup from happening.

If you drive conservatively for a month or more, your exhaust will smell very strong for 2-3 redlines while youre clearing out the carbon.

If your car already has buildup, it will remove a little bit but not all.
 
I've looked into this before buying our CX-5 because I was preparing for it. While car shoping, I found that many of the engines now are Direct Injection, and Direct Injection is the direction future engines are going. They seemed to have improved on the situation from early DI engines 5+yrs ago, but it's an ongoing issue.

With my experience, using logic, and videos I've seen,
what some say about flooring the gas to burst and flow fast high volumes of air across the carbon built up valves, does help remove some of it.

It's not a full solution though.

The best solution is a proper valve clean, but that's not rational unless you've got money.


Of solutions I've researched, Seafoam seems to do the best job. I've already bought 2 bottles of their engine cleaner that I plan to use about every 10k miles.

Here's a list of videos for you to see for yourself,
https://www.youtube.com/results?search_query=carbon+deposit+removal
 
I had a Jeep that suffered from intake manifold buildup. I sold it at 160k miles, and the engine light came on every few months. I was using Seafoam at that point every other oil change, but now that I have the CX-5, I'd like to be more preventative.

I drive 45 miles one-way to work on 50-55 mph roads with a lot of stops. I don't get on the freeway but a couple of times a week, and even when driving on the freeway, when I hit the gas, I don't redline the engine...it gets up to 4k rpms and then I max out the speed limit, lol. I've currently got 12k miles on the CX-5, and it drives great.

Can someone explain exactly how to "redline" the engine if I don't have easy access to a hill? Should I maybe start Seafoaming the CX-5 now, at 12k miles?
 
There was one video that I found to be the most helpful, that I can't seem to find.

They compared water, to something I can't remember, and compared Seafoam.

He first disassembled an old lawnmower engine (not direct injection, but carborator) that had carbon deposits.

He showed the carbon deposit on the head and piston.

1. Disassembled and documented the before.
2. Used the "cleaning solution"
3. Disassembled and documented the after.


This video was the best I've seen on showing how well these things help.

They all helped but to varying degrees and different side-effects.

The worst side-effect was with water. Although water did help to clean the deposits, it seaps around the rings and mixes with the oil and creates other problems.


The one that clearly cleaned the deposits the most was Seafoam, although it creates a lot of white smoke as part of the process.

Keep in mind, none seemed to fully clean the engine to new. If the carbon buildup sat longer, they were harder to remove and the carbon buildup on these engines sat for a while.

This should help show the benifits of Seafoam.
https://www.youtube.com/results?search_query=seafoam+before+and+after
 
Found the video.

It wasn't just one, but a series.

Part 2: Seafoam--can't believe what it did to my engine part 2--throttle body clean!!
https://www.youtube.com/watch?v=YeFat4aMcYg

Part 3: Seafoam--can't believe what it did to my engine part 3--cylinder cleaning test!!
https://www.youtube.com/watch?v=vVyin2n24X8&t=1s

Part 4: Seafoam--can't believe what it did to my engine!!--Episode 4--Compression Test
https://www.youtube.com/watch?v=w9fTKZN0Eps&t=1s

Part 5: Seafoam--can't believe what it did to my engine episode 5--cylinder cleaning test using water!!
https://www.youtube.com/results?search_query=seafoam+before+and+after

Part 6: Seafoam--can't believe what it did to my engine episode 6--Seafoam vs ATF!!
https://www.youtube.com/watch?v=wT0TTGO2CUY



Seafoam vs Marvel Mystery Oil! The Ultimate Showdown!

https://www.youtube.com/watch?v=J3F3jDa2xhg


Does B-12 Chemtool Work? Let's find out!
https://www.youtube.com/watch?v=zEzOsvBwZIY

Just watched the above that compared Seafoam to B-12 Chemtool and now B-12 Chemtool is my favorite.

This data below was the most convincing, that came from that last test,

2017-09-21.png
 
Found the video.

It wasn't just one, but a series.

Part 2: Seafoam--can't believe what it did to my engine part 2--throttle body clean!!
https://www.youtube.com/watch?v=YeFat4aMcYg

Part 3: Seafoam--can't believe what it did to my engine part 3--cylinder cleaning test!!
https://www.youtube.com/watch?v=vVyin2n24X8&t=1s

Part 4: Seafoam--can't believe what it did to my engine!!--Episode 4--Compression Test
https://www.youtube.com/watch?v=w9fTKZN0Eps&t=1s

Part 5: Seafoam--can't believe what it did to my engine episode 5--cylinder cleaning test using water!!
https://www.youtube.com/results?search_query=seafoam+before+and+after

Part 6: Seafoam--can't believe what it did to my engine episode 6--Seafoam vs ATF!!
https://www.youtube.com/watch?v=wT0TTGO2CUY



Seafoam vs Marvel Mystery Oil! The Ultimate Showdown!

https://www.youtube.com/watch?v=J3F3jDa2xhg


Does B-12 Chemtool Work? Let's find out!
https://www.youtube.com/watch?v=zEzOsvBwZIY

Just watched the above that compared Seafoam to B-12 Chemtool and now B-12 Chemtool is my favorite.

This data below was the most convincing, that came from that last test,

2017-09-21.png

Watch out. I heard ....err seen that B-12 eats rubber though. Have you seen the comparo Youtube vid of it eating the tester's gloves? Now imagine your seals. The seafoam is safer.
 
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.
 
http://www.motoiq.com/MagazineArtic...l-introducing-mazdas-skyactiv-technology.aspx

"To eliminate the problem of intake valve deposits that plague current direct gasoline injection engines, the engineers at Mazda determined that deposits are formed when intake valve temperatures fall below 400 degrees C. Measures were taken so that the intake valve would operate above this point to reduce deposit formation."

"One of the biggest issues with direct injection engines is a build up of deposits on the intake valve. Mazda determined that this was largely due to the intake valve being too cool. A lot of analysis went into designing the heat paths away from the valves to keep them at the proper temperature to avoid deposit formation."

Not saying that it isn't a problem, just that we have no data that I'm aware of that it is one. As we get more and more higher mileage SkyActiv engines, I guess we'll see if Mazda's workaround works as intended.
 
I've looked into this before buying our CX-5 because I was preparing for it. While car shoping, I found that many of the engines now are Direct Injection, and Direct Injection is the direction future engines are going. They seemed to have improved on the situation from early DI engines 5+yrs ago, but it's an ongoing issue.

With my experience, using logic, and videos I've seen,
what some say about flooring the gas to burst and flow fast high volumes of air across the carbon built up valves, does help remove some of it.

It's not a full solution though.

The best solution is a proper valve clean, but that's not rational unless you've got money.


Of solutions I've researched, Seafoam seems to do the best job. I've already bought 2 bottles of their engine cleaner that I plan to use about every 10k miles.

Here's a list of videos for you to see for yourself,
https://www.youtube.com/results?search_query=carbon+deposit+removal

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.

Correct. Dont bother with sea foam, its not the best way to keep the valves clean.

I had a Jeep that suffered from intake manifold buildup. I sold it at 160k miles, and the engine light came on every few months. I was using Seafoam at that point every other oil change, but now that I have the CX-5, I'd like to be more preventative.

I drive 45 miles one-way to work on 50-55 mph roads with a lot of stops. I don't get on the freeway but a couple of times a week, and even when driving on the freeway, when I hit the gas, I don't redline the engine...it gets up to 4k rpms and then I max out the speed limit, lol. I've currently got 12k miles on the CX-5, and it drives great.

Can someone explain exactly how to "redline" the engine if I don't have easy access to a hill? Should I maybe start Seafoaming the CX-5 now, at 12k miles?

No, and youre at way too low of a mileage to worry about this. Even at high mileage, seafoam wont help you. I recommend redlining it in second or third gear while merging on the highway so you dont really break the speed limit. Maybe about once a week or so?
 
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.
 
Higher octane fuel would result in a cleaner burn thus reducing carbon build-up. But unless you have an ECU tune like orange virus to make 91 octane fuel compatible with your ECU, youre just wasting your time.

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.

Any grade above 87 is rated to avoid preignition due to engine compression (knock).

BTW, I ran my 2013 CX-5 well past 50K before trading it for the CX-9 and there was never any sign of carbon build up. Ran perfectly fine. Also, I have seen many Skyactiv engines well past 100k that never experience effects of carbon build up. I think the topic is a bit overblown. I havent seen much in this forum of actual owners experiencing carbon issues.
 
BTW, I ran my 2013 CX-5 well past 50K before trading it for the CX-9 and there was never any sign of carbon build up. Ran perfectly fine. Also, I have seen many Skyactiv engines well past 100k that never experience effects of carbon build up. I think the topic is a bit overblown. I havent seen much in this forum of actual owners experiencing carbon issues.

Youre right, I did blow the situation out of proportion a little. Mazda did a great job with limiting the amount of buildup on the valves.

Anyways, i have no idea what it was. Maybe a defective oil filter or something? But I changed the oil a few months back and right away the engine started to make that weird grumbling sound. Changed the oil again today and the engine runs much, much smoother then before. completely stopped making that sound.
 
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.
 
http://www.motoiq.com/MagazineArtic...l-introducing-mazdas-skyactiv-technology.aspx

"To eliminate the problem of intake valve deposits that plague current direct gasoline injection engines, the engineers at Mazda determined that deposits are formed when intake valve temperatures fall below 400 degrees C. Measures were taken so that the intake valve would operate above this point to reduce deposit formation."

"One of the biggest issues with direct injection engines is a build up of deposits on the intake valve. Mazda determined that this was largely due to the intake valve being too cool. A lot of analysis went into designing the heat paths away from the valves to keep them at the proper temperature to avoid deposit formation."

Not saying that it isn't a problem, just that we have no data that I'm aware of that it is one. As we get more and more higher mileage SkyActiv engines, I guess we'll see if Mazda's workaround works as intended.

I do a lot of burn-off tests for lubricants, as relates to weapons. I have noticed that at a certain temp (depends on oil/grease), you will get residue. Keep heating the sample, and the residue in many cases "ashes" and will fall off/degrade/be gone near completely.
 
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