Intake Valve Deposit Cleaning

[JustMe2]

I have a 2015 Mazda 3 2l Skyactiv-G engine, and I'm thinking it might be best to remove the intake manifold and clean the intake valves. Over the past 120k miles, fuel economy (as shown by the infotainment system) has probably decreased by 5-10%. I was planning to remove the deposits using the "zip-tie" method, but I was wondering about using some sort of chemical soak prior to mechanical removal. ChatGPT suggested Berryman B12 Intake Valve cleaner (Part 3012) but it seems next to impossible to get. They suggeted as an alternative: "Total Fuel System Cleaner", while Berryman suggested Intake Valve and Combustion Cleaner (2611), which is expensive and clearly not designed for this application.

I've also heard suggestions of AC Delco Top End Cleaner (which seems to be ridiculously expensive), and Liqui Moly Valve Clean (which is intended to get put in the gas tank). There's always Marvel Mystery Oil, toluene, MEK, brake cleaner (chlorinated?), Techron, etc...

Anyone have any suggestions as to what to use to loosen up carbon deposits before mechanical removal that's available and not absurdly expensive?

 

[PontiacHO]

I’m sure that this is a very unpopular method these days but a mix of water and Marvel Mystery Oil has always worked for me. Find a vacuum port-hose and let the engine pull It in while slightly working the throttle to keep it from choking. If that doesn’t do it the carbon will have to be mechanically removed.

 

[Lubener]

GM Top Engine Cleaner, Berrymans and Kroil are what worked best for me. They are worth the money when you get good results.

 

[CarlB]

I just use a harbor freight media blaster and walnut. Shop vacuum with a cheap intake port attachment. They have a hole for the media blaster to slip through.

The walnut works well enough that no chemicals are required.

 

[dubber09]

Try CRC IVD cleaner first, it should be available at Walmart and it's easy to use.
I have 120k miles on Sportage now and use CRC cleaner every 30k miles or so, never looked at the valves with borescope thou. CRC seems to work to whatever degree.

 

[JustMe2]

Thanks for all the feedback, couple points:

1) Everything I've read is sucking things in through the intake is ineffective and I have no way to verify the results, so I'm committed to removing the intake and mechanically removing deposits. That way I know it's clean and eliminates that as a source of gas mileage decrease.

2) One issue with Berryman's is that it's not one thing they make a ton of products and stupidly they're all called Berryman B12 Chemtool. I don't know how similar they are. The most correct fluid isn't available for some reason.

3) The original plan was walnut blasting and maybe I should stick to that. I can't find any adapter for the Skyactiv G 2l engine. If someone could point me in the general direction that'd be really helpful. I know Corksport had one but I think it's for a different engine. I was thinking I could 3D print something out of TPU, but not sure what the exact design is. Is it just something that sticks into the port by a few mm, and just two parallel holes, one for a vacuum adapter and one to stick the blaster tube through?

 

[Wheel366]

Try CRC IVD cleaner first, it should be available at Walmart and it's easy to use.
I have 120k miles on Sportage now and use CRC cleaner every 30k miles or so, never looked at the valves with borescope thou. CRC seems to work to whatever degree.

I bought 2 cans of this but have yet to do it yet. Might do in January right before my OCI. Gotta get myself some tubing long enough to run through window so I can keep foot on the pedal.

 

[dubber09]

Just put a length of wood between pedal and driver seat.

 

[CarlB]

Thanks for all the feedback, couple points:

1) Everything I've read is sucking things in through the intake is ineffective and I have no way to verify the results, so I'm committed to removing the intake and mechanically removing deposits. That way I know it's clean and eliminates that as a source of gas mileage decrease.

2) One issue with Berryman's is that it's not one thing they make a ton of products and stupidly they're all called Berryman B12 Chemtool. I don't know how similar they are. The most correct fluid isn't available for some reason.

3) The original plan was walnut blasting and maybe I should stick to that. I can't find any adapter for the Skyactiv G 2l engine. If someone could point me in the general direction that'd be really helpful. I know Corksport had one but I think it's for a different engine. I was thinking I could 3D print something out of TPU, but not sure what the exact design is. Is it just something that sticks into the port by a few mm, and just two parallel holes, one for a vacuum adapter and one to stick the blaster tube through?

Got a picture of the port on the head? I didn't buy anything all that specific. It's just a rectangular setup that aids in using some suction while blasting. Honestly a perfect seal was less effective than a slight pressure leak. It's finding the balance, but you just adjust angle and amount of seal as you go.

Edit: I overpaid and use this. I could have just printed something in TPU. https://a.co/d/bnE2QnE

 

[AJB0009]

I just use a harbor freight media blaster and walnut. Shop vacuum with a cheap intake port attachment. They have a hole for the media blaster to slip through.

The walnut works well enough that no chemicals are required.

I have not done it ever. However, I think I would just want to do this, mechanically, and suck it all out. Not soften it and wash that gunk into my engine.

 

[CarlB]

I have not done it ever. However, I think I would just want to do this, mechanically, and suck it all out. Not soften it and wash that gunk into my engine.

That was my primary concern. It's probably a tradeoffs since seems like a non zero chance that a little bit of debris will make it into the cylinder.

The constant suction of the shop vacuum and a closed valve felt better than the chemicals that will absolutely have some level of leakage past the valve.

 

[CarlB]

I'll recap my entire setup. You could definitely do better or worse, but this is what I use.

Media blaster: https://www.harborfreight.com/50-lb-portable-abrasive-blaster-kit-59483.html
Far too much media. It's a lifetime supply, buy less than me if possible. https://www.amazon.com/dp/B07QY98FGW
Adapter for the shop vacuum: https://www.amazon.com/dp/B0CSVL9TDQ
Extension for the wand: https://www.amazon.com/dp/B0B6TKX1XF

Before:

After:

 

[AJB0009]

I'll recap my entire setup. You could definitely do better or worse, but this is what I use.

Media blaster: https://www.harborfreight.com/50-lb-portable-abrasive-blaster-kit-59483.html
Far too much media. It's a lifetime supply, buy less than me if possible. https://www.amazon.com/dp/B07QY98FGW
Adapter for the shop vacuum: https://www.amazon.com/dp/B0CSVL9TDQ
Extension for the wand: https://www.amazon.com/dp/B0B6TKX1XF

Before:
View attachment 307769
After:
View attachment 307770

That looks nice!

 

[shortyb]

Before I got a media blaster, I used the "zip tie"method and Berrymans B-12 Chemtool Fuel Injector Cleaner (# 0116 for 16oz. can). Make sure all valves are closed at TDC (duh) and pour it in. Depending on how badly carboned up it is, I'd let it soak for at least an hour, then go crazy with the ties. I would usually have to use a pick on the stems to get the really stubborn crud off. It works, but is very labor intensive. The blaster is way easier, just costs more up front.

 

[JustMe2]

I'll recap my entire setup. You could definitely do better or worse, but this is what I use.

Media blaster: https://www.harborfreight.com/50-lb-portable-abrasive-blaster-kit-59483.html
Far too much media. It's a lifetime supply, buy less than me if possible. https://www.amazon.com/dp/B07QY98FGW
Adapter for the shop vacuum: https://www.amazon.com/dp/B0CSVL9TDQ
Extension for the wand: https://www.amazon.com/dp/B0B6TKX1XF

Before:
View attachment 307769
After:
View attachment 307770

Wow! That's a lot of good info. Thanks! Maybe I'll just do the media blast... Any reason you didn't get the walnuts from HF, I think it's $25 for 25 lbs.

The manifold looks like this:

https://ebay.us/m/sgeFpH

So I guess the best way to describe the ports is a rectangle with different radiusing on the top versus the bottom, assuming you're in one port per valve.

I asked ChatGPT and it said you could make your own adapter out of PETG and gave me a parametric design. How good it is, who knows...

 

[Mainia]

I'll recap my entire setup. You could definitely do better or worse, but this is what I use.

Media blaster: https://www.harborfreight.com/50-lb-portable-abrasive-blaster-kit-59483.html
Far too much media. It's a lifetime supply, buy less than me if possible. https://www.amazon.com/dp/B07QY98FGW
Adapter for the shop vacuum: https://www.amazon.com/dp/B0CSVL9TDQ
Extension for the wand: https://www.amazon.com/dp/B0B6TKX1XF

Before:
View attachment 307769
After:
View attachment 307770

How long did it take roughly per port to clean like the picture? Was it 100% blasted or did you pick away manually at all?

 

[xspeedy]

Stupid question, but couldn’t you just soak and then put a long and narrow brass wire brush on a drill or dremel with a flex extension and go crazy?

 

[CarlB]

Wow! That's a lot of good info. Thanks! Maybe I'll just do the media blast... Any reason you didn't get the walnuts from HF, I think it's $25 for 25 lbs.

The manifold looks like this:

https://ebay.us/m/sgeFpH

So I guess the best way to describe the ports is a rectangle with different radiusing on the top versus the bottom, assuming you're in one port per valve.

I asked ChatGPT and it said you could make your own adapter out of PETG and gave me a parametric design. How good it is, who knows...

They were out of stock, Amazon wasn't. I wouldn't want anything too fine, so can't speak for HF since it wasn't available for me to look at.

 

[CarlB]

How long did it take roughly per port to clean like the picture? Was it 100% blasted or did you pick away manually at all?

All blast + vacuum. Was just a few minutes per valve once they are at TDC. That's including stopping to visually review, blast or vacuum more. Once done you end up playing with the level of seal/leak to get all the media out.

 

[JustMe2]

Stupid question, but couldn’t you just soak and then put a long and narrow brass wire brush on a drill or dremel with a flex extension and go crazy?

View attachment 307789

Not a stupid question, I've considered that, but I'm concerned brass could do damage and it might be hard to get full coverage. Also, you need to be extra careful you don't lose any bristles down there.

For whatever reason, the preferred way of you aren't using a walnut blaster is using a bunch of nylon zipties. But Carl's whole setup is less than $100 and is faster and does a better job... so... I'm just going to spend the money.