Case report: Fiesta ST intake valves carbon build up analysis

[rbr]

I'd like to see what difference Aux fuel makes, because if the deposits are already caked on there... Would they just come off from the aux fuel? Or once they're caked on they need to be blasted with media to be removed?

I'm at nearly 100k now and curious to know what mine look like, but I just had a newborn and don't necessarily have time to rip my car apart lol. I've been using aux fuel on/off for ~40k miles now.

Could you enlighten me about this aux fuel folks are talking about?

I assume you/they are talking about alternative fuel systems, like butane pentane mix (lpg ) or methane or e85?

 

[rbr]

I'd also like to compare this to a FiST with a catch can, just to see how much difference it makes.
But, I'M not gonna do it myself, so I can't judge anyone. Just like I don't do dyno runs after every change in the engine. Just not practical.
Kudos to those who bring us this info.

I posted this report in r/fiestast subreddit and am in contact with a guy running a catch can since 3k miles who is now on 60k and is planning on pulling the head. I am in contact with him and he promised to provide pictures when he gets to it. So, stand by for more data relating to the catchcan on a later date

 

[rbr]

One of the most used methods is walnut blasting but get ready for that sticker shock. I got quoted near $1000 to R&R intake and walnut blast intake ports. Not going to do it at this point. Ill wait until performance is reduced to even start thinking about that.

Indeed, this is most often used. I used 10 bucks worth a carb cleaner and a lot of swearing.

If anyone is to follow in my footsteps, take off the bumper. Thank me later.

 

[jeff]

I'd also like to compare this to a FiST with a catch can, just to see how much difference it makes.
But, I'M not gonna do it myself, so I can't judge anyone. Just like I don't do dyno runs after every change in the engine. Just not practical.
Kudos to those who bring us this info.

Yeah that would be optimal but unlikely it will happen. In the meantime I've recovered about 20 ounces of blow-by in my 6 years of owning the car.

 

[Lays]

Could you enlighten me about this aux fuel folks are talking about?

I assume you/they are talking about alternative fuel systems, like butane pentane mix (lpg ) or methane or e85?

Port injection in the throttle body, provides fuel splash on the back of the valves like traditional fuel injection, lots of people say it will "clean them"

I'm curious if it prevents the build-up only, or if it can clean deposits that are already formed.

 

[TyphoonFiST]

Could you enlighten me about this aux fuel folks are talking about?

I assume you/they are talking about alternative fuel systems, like butane pentane mix (lpg ) or methane or e85?

There is SPI/ Single port injection at the throttle body.....

https://www.stratifiedauto.com/index.php?main_page=product_info&cPath=117_124&products_id=306


Then there is 4 port intake injection that has a fuel rail with injectors between the intake manifold and the cylinder head. It sprays evenly into each intake runner onto the valves on its way into the engine.


https://www.stratifiedauto.com/index.php?main_page=product_info&cPath=117_124&products_id=723


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[Old Mike Emerson]

Greetings,

I know that there is a very long thread active on this forum on this topic. This being said, this will not be a discussion or a question. This is a case report, as far as i know the first documented on the net for the Fiesta ST. Because of this i thought it warranted a thread post ( however, if mods disagree, i can happily change this into a post within the current thread)The post is made for informational purposes and to help others avoid the same mistakes i did.

Motivation and scientific background:

As we all know, DI engines without redundant injectors all suffer from carbon build up to some degree. The current paradigm based on the posts on this and other Fiesta ST based forums claims that in comparison to VAG products Ecoboost engines do not suffer from carbon build up. This claim is supported by an abundance of VAG related carbon build up problem video's, and a curious absence of Ecoboost focussed one's. This being said, absence of evidence is not evidence of absence. Thus i wanted to validate the current paradigm and test out the following hypotheses:

1: Ecoboost engine's do not suffer from a carbon build up on the intake valves.
2: If build up is present, it is insignificant and does not impact the performance of the engine
3: If no build up is present, could this possible come from the use of the CDC valve cleaner product?

Methodology
First, i would like to apologise for the fact that i did not do the case study on a "clean" subject. With un-clean subject i mean that the car is not completely stock and i have used a CDC valve cleaner product prior to disassembly (2k miles back. However, if you read the results you will see that this did not effect the conclusion in any way).

To test both hypotheses i had to take off the intake. So, that's what i did.
The guinea pig for this test was a 2014 Fiesta ST 1.6 Ecoboost with a bit above 60k miles, stock tune and Airtec intercooler. Full maintenance history. Vehicle has been mainly used by me and by previous owner's for spirited driving and auto cross. I estimate 60% of total miles to be of the highway variety. First
Prior to disassembly vehicle did not show any significant indicators of running rough. The only thing worth mentioning is rough running after sitting for a week+ the first minute.


Results
Bad. Based on the VAG video's the carbon build up on the Fiesta is comparable to the VAG counterpart. I mean, see the pictures.

1: Fords do absolutely suffer from carbon build up. Again, see the pictures

2: Absolutely NOT. After cleaning, i directly noticed that the car ran much smoother and had more "oompf". I think reason why i noted prior to disassembly that the car did not run rough was because it didn't. However, not running rough is definitely not the same as optimum operation. While you could claim that my conclusion can be caused by placebo effect, i would counter with my butt dyno. I definetly noticed a difference.

3: For cleaning valve's, this stuff is useless. Again, see pictures. This is after the treatment. This means that either the valve fouling was ever worse, or it can only help when valve are clean to prevent future build up.


Summary:

While this is only a case study my car clearly shows that fiesta's suffer from carbon build up. And while not causing catastrophic damage, it prevents the engine from running optimally. I would encourage others to research this issue further and possibly expand the literature with case studies of long term usage of catch cans and different types of driving styles.

As soon as it gets warm in Ohio, I plan on taking my manifold off just to see what the intake valves look like at 7,800 miles. I will post those pictures here and also send them to you, so you have more information.

 

[M-Sport fan]

One of the most used methods is walnut blasting but get ready for that sticker shock. I got quoted near $1000 to R&R intake and walnut blast intake ports. Not going to do it at this point. Ill wait until performance is reduced to even start thinking about that.

That quote was not from Mitch, ex C-PE employee, was it?
(I ask because he moved back to the Baltimore area, and he was doing this procedure while still at CP-E there.)

 

[rbr]

Port injection in the throttle body, provides fuel splash on the back of the valves like traditional fuel injection, lots of people say it will "clean them"

I'm curious if it prevents the build-up only, or if it can clean deposits that are already formed.

Probably both. I am sure that's the ticket for solving the problem permanently.

As soon as it gets warm in Ohio, I plan on taking my manifold off just to see what the intake valves look like at 7,800 miles. I will post those pictures here and also send them to you, so you have more information.

Ohh yeah papi, data engineer at work and in private. Dat data point lyfe.

 

[dhminer]

I'd also like to compare this to a FiST with a catch can, just to see how much difference it makes.
But, I'M not gonna do it myself, so I can't judge anyone. Just like I don't do dyno runs after every change in the engine. Just not practical.
Kudos to those who bring us this info.

I’ll stick the borescope up in there when I’m installing single port aux. I ran most of my 73k miles without the catch can though, so not sure how much help that’ll be, if any. Mine are probably worse than OP but will give some starting point to go back and check a year later and see if aux fuel cleaned the gunk off.

 

[kevinatfms]

That quote was not from Mitch, ex C-PE employee, was it?
(I ask because he moved back to the Baltimore area, and he was doing this procedure while still at CP-E there.)

It was not. Once CP-E denied my warranty claim on their busted ass mount i gave up dealing with them.

It was a local company in my area that started up doing this. They are mainly a machine shop for engine building and are not Ford or Fiesta specific. They have done a few BMW's and a few Focus cars from people who suggested them. Not knocking them but the price was just too much for something that hasnt shown to degrade my performance to date. If it starts to degrade i will look into other methods of cleaning before shelling over $1000 for walnut blasting.

 

[rallytaff]

Since simply changing my plugs at 98,000 miles, my car has a noticeable difference in acceleration and running better than the day I bought it 7yrs ago! Have no leaks anywhere. I must have got a good one!

 

[The_Ryan]

It was not. Once CP-E denied my warranty claim on their busted ass mount i gave up dealing with them.

It was a local company in my area that started up doing this. They are mainly a machine shop for engine building and are not Ford or Fiesta specific. They have done a few BMW's and a few Focus cars from people who suggested them. Not knocking them but the price was just too much for something that hasnt shown to degrade my performance to date. If it starts to degrade i will look into other methods of cleaning before shelling over $1000 for walnut blasting.

Performance degradation happens so slowly that it's hard to realize how much of a difference it makes, but once it's done you'll notice it. It costs me $250 from a local guy for Walnut blast. If it cost close to $1000 then I'd say it's not worth it yet

 

[M-Sport fan]

Performance degradation happens so slowly that it's hard to realize how much of a difference it makes, but once it's done you'll notice it. It costs me $250 from a local guy for Walnut blast. If it cost close to $1000 then I'd say it's not worth it yet

That is a bargain and a half for that service!

It would actually pay for me to drive up there, stay overnight at a hotel, and get it done and then drive back, since I am sure that anyone doing it in this area would be charging the same as that place near Kevin, OR MORE!

 

[HAHAFiST]

Performance degradation happens so slowly that it's hard to realize how much of a difference it makes, but once it's done you'll notice it. It costs me $250 from a local guy for Walnut blast. If it cost close to $1000 then I'd say it's not worth it yet

Jeez where do you live? California it’s like 5-600.


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[TyphoonFiST]

Jeez where do you live? California it’s like 5-600.


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California is why it's that expensive * shop around*

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[The_Ryan]

That is a bargain and a half for that service!

It would actually pay for me to drive up there, stay overnight at a hotel, and get it done and then drive back, since I am sure that anyone doing it in this area would be charging the same as that place near Kevin, OR MORE!

The shop is in NH, so you can hit the slopes afterwards!

Jeez where do you live? California it’s like 5-600.


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In Boston, and that's from a local ST/RS specialist, I think the price recently went up to $300-350 but still good and totally worth the service. He said he was able to find a way to get the manifold off without taking off the alternator and some other bits thus saving some time.

 

[HAHAFiST]

The shop is in NH, so you can hit the slopes afterwards!



In Boston, and that's from a local ST/RS specialist, I think the price recently went up to $300-350 but still good and totally worth the service. He said he was able to find a way to get the manifold off without taking off the alternator and some other bits thus saving some time.

I'm curious how he did that, ha. Seemed like it was required.

 

[HAHAFiST]

California is why it's that expensive * shop around*

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Lol, don't have to tell me twice. I just paid $60 USD to fill my tank with 12.4 gallons of crappy 91 octane.

 

[Woods247]

It was not. Once CP-E denied my warranty claim on their busted ass mount i gave up dealing with them.

It was a local company in my area that started up doing this. They are mainly a machine shop for engine building and are not Ford or Fiesta specific. They have done a few BMW's and a few Focus cars from people who suggested them. Not knocking them but the price was just too much for something that hasnt shown to degrade my performance to date. If it starts to degrade i will look into other methods of cleaning before shelling over $1000 for walnut blasting.

Damn I just got quoted $350. I suppose I’m lucky.