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Discussion Starter · #1 ·
I'm starting this thread to create a place to post photos of intake valve carbon deposits. I will be periodically taking borescope photos of my valves to keep track of how they are doing and posting them here. Other people are welcome to add their photos, but if you do please note your mileage and any mods or carbon/fuel cleaner products you've used.


To start off here's a photo of the valves on my 2020 VN with performance pack at 1,500 miles. Completely stock car, no catch cans or anything. Oil was changed at 750 miles with Pennzoil Euro LX 0W30. You can see some oil film on there that's collected carbon, so the accumulation has started but isn't more than I would expect. (Note scrape mark on stem is not actually a scrape and is only from the plastic camera head)






For those who have never seen what fairly bad valve deposits on a GDI engine look like, here's a photo of a Ford Ecoboost 2.0L with 60K miles on it that was in for routine walnut blasting service. (Sorry I forgot to grab the after photo from the borescope). Notice the lump of carbon that accumulated on the stem where the oil seepage from the valve guide collected the carbon soot before both were baked on solid by the heat. There's also a hard as glass 2mm thick later of carbon on the back of the valve.


 

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You can see some oil film on there that's collected carbon
It's not oil film, it's carbon from water/fuel/oil vapor passed thru the engine by the PCV and CCV Systems. It effects GDI's from every manufacturer. Most of it is dependant upon the amount of blowby, fuel dilution in the oil, water vapor and how the car is run. If you're poking around on in stop and start traffic and short trips, you're going to have more.

It's the nature of the beast. Do a professional BG Chemical intake valve and top cylinder cleaning every 15K and you won't have any difficulty. Ignore it and you'll be doing a teardown manual cleaning at around 55K or more.
 

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Discussion Starter · #3 ·
At this point in time it's still mostly oil film, it hasn't baked on yet. I was able to scrape it to clean metal with a rubber tipped camera probe. You're right it will bake on there though given a bit more time I think. I'd be curious to see what other people's looks like at this mileage. I do a lot of short trip driving, the yellow lights just barely go away before I pull into work. I usually make a point to take a long drive two days a week to get rid of the fuel dilution in the oil and go beat the car on the mountain roads at least once a week to keep the pistons clean and my stress level down. I'd bet someone who's doing longer daily trips would have less valve deposits, but maybe drier with more hard carbon.



On the second photo, of the ecoboost.. that one is baked on carbon. That's a conventional EGR motor so it's a lot drier because the carbon soot to oil vapor ratio is more soot than oil. That stuff just blew off in big chunks like shattering glass.



I have another photo of an Ecoboost 1.6L that had 100K on it before coming in for blasting. That one the valves had heavy hard carbon deposits with a layer of softer sludge and then wet oil over all of it. No external EGR valve on that one, it's more like our engine, so less combustion soot and more deposits from crankcase vapors and valve guide seep. I expect that's how ours will build up, absent a catch can.


I'm planning to try the BG service on the car at 5K, because, well I won't say why because I don't want to get sued by BG. I'm expecting to do a mechanical carbon removal with my walnut blaster at 30K though. It's easy enough to pull the manifold I don't see a reason to put it off longer than that. Plus it's one of those maintenance things that's really satisfying to do, to see the before and after, so I don't mind it at all.
 

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Most won't offer the service at 5K.

You'll also have to do more than remove the intake manifold. The head needs to come off completely. So, results in a removal of the TB and linkage, Intake Manifold, various sundry parts, removal of the head from the block and a through cleaning by blasting and chemical. You can't stop walnut media from running thru the motor and it's not good for it either. YOu get it in a bearing surface and you're going to damage the crank. I've done it many times. Some, have to be hand scraped along with a valve job. Again the service, is not required until 15K and every 15K afterwards. it will keep it clean and running well.
 

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I'm not too familiar with walnut blasting and what it involves, nor am I familiar with what "TB and Linkage" is. I assume when you say walnut media, you mean any walnut bits left behind after servicing your vehicle with a walnut blaster? I don't exactly have the best knowledge or money for the tools to do this myself, I don't think, so I'd probably get my vehicle serviced by a shop. What risks are there from doing a walnut blast job? I drive about 30-45 minutes each trip to and from work in my VN, so I guess my buildup won't be as much? Also, is it recommended to get a catch can for this car based on the carbon buildup potential? Pardon my many questions, but I'm very curious to know and I haven't exactly had the time to go searching this up myself :( I've been doing so many things lately.

I had all this written up yesterday and never posted this ^ lol.
 

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You'll need to move the intake manifold back from the head.

Throttle Body (TB).

A catch can is optional if you feel like it may help you, then do so. It has some benefits for engines that have a lot of blowby

Walnut media blasting carbon deposits is one way of removing carbon deposits from a GDI engine. The cylinder head need to be removed to access the piston top and intake valves where the primary problem exists. This can happen from 50K-65K miles if the owner isn't taking proper care of the engine. Some GDI engines are worse than others; VW, Ford, Hyundai (1.6T Gamma), Honda and a few others.

A good way to help prevent such buildup is;

1. Run the car at longer intervals.
2. Stay away from as much slow, stop and go traffic as possible and short trips.
3. Have the intake valves cleaned by doing a BG Chemical Cleaning every 15K miles to preclude the build up.
4. Utilize some Chevron Techron every 1200 miles to keep the fuel injectors clean and spraying well.
5. Add some Cerma oil additive as prescribed; https://www.cermastore.com/
6. Change oil every 3-5K miles utilizing a good top grade 5W30 oil.
7. Utilize top tier premium fuel the highest you have available.

Doing the above will provide the most protection from carbon buildup in most GDI engines. it will happen despite doing all this but it will certainly minimize its effects.
 

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What about adding a meth injection kit. That would help keep the valves clean also. Plus lower IAT's. And higher octane with the 93 I'm using now. I've been going back and forth on this idea. But to utilize meth to it's potential you need a tune. A tune voids warranty. So dilemma.. ha
 

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No it won't help keep intake valves any cleaner. That's a myth. What it will do is; with the added Methyl Alcohol it will increase seal deterioration and decreasing the life of the motor. This engine is set up for E-15 not E75/85. Too high an ethanol fuel, shortens the life of the motor. It's wasn't designed as a Flex Fuel Vehicle.
 

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Discussion Starter · #10 · (Edited)
I'm not too familiar with walnut blasting and what it involves, nor am I familiar with what "TB and Linkage" is. I assume when you say walnut media, you mean any walnut bits left behind after servicing your vehicle with a walnut blaster? I don't exactly have the best knowledge or money for the tools to do this myself, I don't think, so I'd probably get my vehicle serviced by a shop. What risks are there from doing a walnut blast job? I drive about 30-45 minutes each trip to and from work in my VN, so I guess my buildup won't be as much? Also, is it recommended to get a catch can for this car based on the carbon buildup potential? Pardon my many questions, but I'm very curious to know and I haven't exactly had the time to go searching this up myself :( I've been doing so many things lately.

I had all this written up yesterday and never posted this ^ lol.

About walnut media valve cleaning..


This is the approved cleaning method of several OEMs, including BMW and Mercedes. No blast media enters the engine past the valves, none of it remains in there when the procedure is finished, and the walnut media that's used is non abrasive organic material that cannot cause engine damage even if any stray particles are somehow missed. I've tried other methods over the past 12 or so years since I started working on DI engines and the walnut blast method is by far my favorite method to get the best results. I've done dozens and dozens of walnut valve cleaning procedures.


The procedure goes like this:

After removing the intake manifold each cylinder is done individually because each one has to be cleaned at TDC on the compression stroke so that the valves are closed. All other intake ports are plugged (I use foam plugs like big earplugs). No media goes past the valve (and there is no way for it to reach the oil system or especially a bearing surface even if it did). The blast machine has a nozzle that blasts clean walnut shell media into the port at the valve and removes the carbon entirely down to clean metal (but does not remove any metal). The machine has a vacuum attachment that collects the media as it bounces back out of the port along with the removed carbon and collects it in a shop vac for disposal. Any residual dust left in the intake port is blown out with compressed air before reinstalling the intake manifold. The media leaves the port and valve stem and neck clean and dry like brand new.


When you do this as a maintenance procedure you only remove the intake manifold. There's no need to remove anything else. It's a completely safe procedure and is actually safer when dealing with heavy carbon than chemical cleaners are because the carbon is removed and not allowed to break free and run through the engine. With chemical cleaners the carbon has to exit the engine by going through it and through the turbocharger and catalyst. If any large pieces break free at once it has potential to cause damage to the turbine wheel of the turbocharger (this was a concern Ford listed when they prohibited chemical carbon removal on their DI engines).

Modern cars don't have "linkage" for the throttle body to worry about removing. The throttle body is a fully enclosed electronic unit with one electrical plug and no cables or linkages. All of the moving parts are sealed inside of it and in most cases you don't even need to remove the throttle body from the manifold to remove the manifold from the engine. On our engine the manifold removal is very simple and is about a 30 minute procedure. Total time for a media blast cleaning on this car I figure will be about 2 hours.

The only type of carbon buildup that could require head removal is carbon that's built up in the combustion chamber or on the valve seats but that's not the sort of carbon deposits I'm really talking about here. Those type of deposits (on a healthy motor without other problems) can be avoided by doing intake valve cleanings on time, keeping the valve clearances in adjustment, using top tier fuel, the old "Italian Tune Up" and maybe the occasional bottle of a good fuel injector cleaner (one that's DI safe). It's not common for them to get so bad they need the head off to clean it.



What needs to be removed to get the borescope in there?



The spot I put the borescope through was the port for the sensor (it was either an IAT or MAP, I don't recall) that's right in the middle of the manifold pointing straight forward. Just one screw to take the sensor out but it takes some persistence to get the probe to go up, around, and down into the port to the valve without snagging. I was using an Autel MV108 camera which has a nice small probe tip with nothing to snag on the way back out.





What about adding a meth injection kit. That would help keep the valves clean also. Plus lower IAT's. And higher octane with the 93 I'm using now. I've been going back and forth on this idea. But to utilize meth to it's potential you need a tune. A tune voids warranty. So dilemma.. ha

I had good luck with meth injection on one of my other cars, but it wasn't a DI engine. It was worth it though from a performance standpoint. It let me run enough boost for another 47whp past where I was pinging on pump gas and the engine did that for 200,000 miles and never blew up.


As far as WMI on this car... I would love to do a hardcore multiport WMI setup with a progressive controller and then have the car dyno tuned with a reflashed cloned ECU. I can see that being able to get 400whp out of one of these cars with supporting mods. It would void the warranty for sure though and I'd rather put that sort of money into my other car (to be fully honest) since the VN is supposed to be my "keep it simple" daily driver.


I've heard the same as what Red says though, it won't remove carbon buildup from the intake valves. It sprays only under boost and that's just such a small amount of time overall on a street driven car. Also, methanol is not a great solvent for oil as methanol is a polar molecule and motor oil is non-polar. So meth doesn't wash the oil and carbon off the valve nearly as well as gasoline (which is non-polar like oil) will.

However.. I recall that some people run isopropyl alcohol either with or instead of meth in their WMI systems (a lot of talk about it on the Devils Own forum anyway). Isopropyl is a primarily non-polar molecule that's also slightly polar and readily dissolves oil but also dissolves into water. I wonder if isopropyl wouldn't clean the valves a lot better than meth does. I'd love to test this out and see if it works. I almost want to buy a cheap GDI car just to experiment with. The only concern I can think of is that iso might dissolve into the oil on the cylinder wall more readily and increase oil dilution or cause other unintended side effects that meth doesn't.

I disagree with Red on WMI causing problems with rubber fuel system components. Yes methanol will swell butyl rubber. I didn't have any issues with it eating or swelling the rubber parts on my eclipse though, and I think it's because it's not really soaking them constantly because injection is relatively infrequent and the methanol is diluted. They're not constantly in contact with it in high concentrations like in a fuel supply system.

This car likely doesn't use butyl rubber o-rings or seals anywhere in the intake though anyway. The o-ring I saw on the sensor I pulled looked to be either nitrile or fluorosilicone/silicone either of which aren't effected by alcohols. I know the intake gasket and throttle body gasket are fluorosilicone for certain.


I'm just waiting on that Forge catch can to come out because that's what I plan to do, along with top tier gas and GF-6 oil as soon as it hits the market.
 

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Isopropyl is denatured denatured ethyl alcohol. Methanol is wood alcohol. Both in high enough quantities will damage engine seals with continuous use. Isopropyl will raise the level of ethanol in the system, as it's injected directly into the fuel charge. The VN is set to run on a maximum of 15% ethanol. What you're getting from the pump is mainly 10% ethanol at the moment, However, slated to be raised to 15% with in the next year nationwide.

What seals the VN engine utilize are; polyurethane, rubber or PTFE. The chart below will give you a very good understanding what can be utilized in ethanol of less than 15% ethanol. As the percentage of alcohol goes up, the resistance goes down. You can't run anything near E75 or E85 without changing seals over the long term. They utilize special seals.
http://www.mossrubber.com/pdfs/Chem_Res.pdf
 

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Discussion Starter · #12 ·
Isopropyl is denatured denatured ethyl alcohol. Methanol is wood alcohol. Both in high enough quantities will damage engine seals with continuous use. Isopropyl will raise the level of ethanol in the system, as it's injected directly into the fuel charge. The VN is set to run on a maximum of 15% ethanol. What you're getting from the pump is mainly 10% ethanol at the moment, However, slated to be raised to 15% with in the next year nationwide.

What seals the VN engine utilize are; polyurethane, rubber or PTFE. The chart below will give you a very good understanding what can be utilized in ethanol of less than 15% ethanol. As the percentage of alcohol goes up, the resistance goes down. You can't run anything near E75 or E85 without changing seals over the long term. They utilize special seals.
http://www.mossrubber.com/pdfs/Chem_Res.pdf

What? I'm not talking about dumping it into the fuel tank. It would have zero contact with any parts of the fuel system. It goes into the water/meth tank and through the WMI system which I really hope would be fully alcohol safe. I thought I explained that pretty clearly, I feel like you didn't even read all of it.



Also, the chart you posted contradicts everything you just said :confused:. All of the rubber types they list as automotive use are listed as alcohol safe and so is PTFE and polyurethane isn't used in engines at all because it has really poor oil resistance.


I don't really want to argue with you about stuff all the time. I'm not here for that. I feel like you keep trying to find things wrong with what I post. Why? What's your goal with this?
 

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@4k

2020 pp at 4,247mi looking good so far. Oil changes at 766 mi & 3294 mi. Currently using pennzoil platinum 5w-30.
 

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2020 pp at 4,247mi looking good so far. Oil changes at 766 mi & 3294 mi. Currently using pennzoil platinum 5w-30.
Looks good! Have you used any fuel injector cleaner? Do you have an oil catch can? What are your driving habits? Any track days? Thanks to all who are posting up this extremely important information for others to see. It is much appreciated!
 

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Looks good! Have you used any fuel injector cleaner? Do you have an oil catch can? What are your driving habits? Any track days? Thanks to all who are posting up this extremely important information for others to see. It is much appreciated!
No supplemental fuel injector cleaner, but have only used top tier gas (I think I saw in the manual FI cleaner is only necessary every so often if not using top tier... which makes sense to me).

No oil catch can.

Habits... I’d call spirited commutes (when traffic and conditions allow... I like hearing the pops and bangs and making the shift indicator lights flash once in a while). I will say my neighbor caught me out in the wild once and felt compelled enough to call me immediately and give me a lecture... the downsides of choosing Performance Blue I suppose. :(

Fuel Econ per tank has ranged from 25.3 to 28.1 (if that says anything).

No track days...yet?
 

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FI Cleaner Hyundai rebottled (Chevron Techron), will be added by the dealership at particular service intervals. If you're not doing dealership service, do so yourself at 3000 mile intervals.
 

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What? I'm not talking about dumping it into the fuel tank. It would have zero contact with any parts of the fuel system. It goes into the water/meth tank and through the WMI system which I really hope would be fully alcohol safe. I thought I explained that pretty clearly, I feel like you didn't even read all of it.



Also, the chart you posted contradicts everything you just said :confused:. All of the rubber types they list as automotive use are listed as alcohol safe and so is PTFE and polyurethane isn't used in engines at all because it has really poor oil resistance.


I don't really want to argue with you about stuff all the time. I'm not here for that. I feel like you keep trying to find things wrong with what I post. Why? What's your goal with this?
Don't even worry about it man he's been known to do this on both Veloster N forums (American and European). He just likes to provoke because I guess that brings him pleasure. He is not interested in sharing info or even reading your content in order to have a good intellectual back and forth conversation that increases knowledge in the community.

Really great info and posts here man thank you it is appreciated. My VN right now is at 11K miles running a catch can and fuel additives twice every oil change. I'm looking forward to borescoping my valves and posting some photos as well. Again man great content!
 

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How exactly will fuel additives help your valves?
 
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