What is needed is for someone that has an old intake valve with carbon on it, heat it up to engine temp, and spray it with one of these products to see what happens.

See if the carbon softens up at least.

Or do what the chap with the Porsche V8 did.

This could be an interesting thread:

https://www.jaguarforums.com/forum/x...-found-228022/

We have done this experiment for trillions of miles.

Why does a direct injection intake valve have carbon buildup and the port injection does not.
Its because of the detergent mandated by law added to gasoline cleans the valve.
That cleaner is PEA.

So the clean valves you see in a port injection engine is PEA at work.
Before detergents, PI engines had similar carbon problems as DI does now.

Also noteworthy is that while every reputable company from Dupont, 3M, Chevron, Shell, CRC, has demonstrated PEA works- and risked their reputation and deep pockets.
None of the driveway video makers who have nothing to lose have ever demonstrated scientifically that it doesnt work.

I think you missed my point.

I fully understand that on a continuing basis PEA can keep a valve clean in a port injected system as it washes over the inlet valve every time it opens.

What I am looking for is its effect on a valve that already has a heavy deposit of hardened carbon on it as in a DI engine which has not been subject to this washing effect.

Where one sprays the stuff through the inlet according to some procedure.

I certainly wont be buying after watching this

If I saw the mileage correctly at just over 170,000 that carbon build up does not look that bad.

It's funny that the before and after video don't have the same lighting!

Since NO INTAKE VALVES shown, I guess it shows nothing.
Pre-combustion deposits are different than post-combustion deposits.

just as well then but this horse aint drinking it lol

In my opinion it would take a too long to clean heavy deposit with chemicals and ill advisable. Like drinking green tea to cure cancer in its final stages.
The objective of the intake PEA spray is to remove moderate deposits and prevent addition formation. It requires multiple and ongoing application. Then you mimic the effects of valve washdown in port injection.
That's the beauty of CRC, they have made the above possible by being $15 an application.

Have you considered a water/meth injection system where the spray is constant with the engine running?

You say that spraying in PEA every so often to remove moderate deposits works. How do you know that?

Some people just love snake oil. Hey, if it makes you feel good, do it.
To remove carbon buildup, have the dealer do walnut blasting. All manufacturers dealers do it for one reason and that is because it is the most cost effective and efficient way to remove carbon build up on on a DI engine. I finally walnut blasted the intakes on the Pig V8 and it runs better than ever, takes maybe a few hours to do and they are now spotless.

My suggestion is all about keeping the inlet valves clean NOT removing hard deposits that are already there.

I do not believe that PEA can remove deposits that are already there.

Water injection, its fantastic. But cleaning the combustion area is not a priority.

In this engine order of priority is, keeping oil passages clean- that encompasses, tensioner, VVT, rings- i.e. the known failures
Fuel injectors clean (not from inside out- but also the outside)
Taking the edge off carbon on the valves.
And there are lots of other ancillary benefits- cleaning cats, plugs, oil level sensor.

How do I know spraying PEA often works on moderate deposits?
Seen many companies making products to do it that way for many years, including 3m and Dupont, but never trusted them.
I really trust CRC- they have a tremendous reputation in my books, there isnt a product I have used of their from MAF cleaner to corrosion inhibitor that hasnt been all about honesty.

I think the problem arises from people believing they can go 10 years and then one day do something about it, and expect to see results that day.