I don't believe that. I don't believe because I watched youtube videos where a gentleman tried couple of methods and eventually got much better result and he verified all processes using camera.
He uses chemical soaking overnight then steel brush and flat screw drivers,
Other people uses sea foam or other additive also confirmed little effect. People tend to believe the effect as they convince themselves after spent money. Unless one shown photos before/after inside intake and cylinder, they are just thinking.
Most carbon is in intake and can be pretty hard, and any additive in fuel won't help.
If you don't repair car, get rid of IS250.

 

Will not driving the car so much slow the carbon build up?

 

Should do it. Just park it in the yard and call it good. lol

Another mega factor is short trips and not reaching operating temperature. You see, each time the engine is stopped, combustion gasses from the intake valves being open dissipate back into the intake track.

Reaching full operating temperature from >25min of operation and pulling higher RPM's allows some of the intake deposits to solidify and be burned by combustion. 10 min trips simply add to the build up.

 

Agree. the SeaFoam spraying process is easy, but that doesn't mean the cleaning is easy.

I've proven this on my 2006 GS300 with 114K miles at the time in my YouTube videos:
1. Light carbon coating on piston tops became soft after few hours of soaking with Chem-Dip. And then driving on the highway burns off the softened carbons.
I confirmed with before and after videos.



2. For hard baked-on carbons on intake valves, even soaking it overnight with chem-dip, only moderately soften the outer layer.
I had to used steel brush and flathead screwdriver to scrape off small chunks of carbons at a time.
This took a long time to clean all 12 valves on 2006 GS300.

Note that I had used 1 can of SeaFoam spray about 10K miles previous to this chem-dip soaking,
so obviously SeaFoam didn't do a good job on heavy and hard baked on carbons.


3. I do think that SeaFoam will help, but only if you use couple cans regularly like every 5-10K miles or so,
before the carbon build up becomes too thick and super hardened.

I now know, how bad carbon build up can be on Lexus GDI engines.
That manual scraping of carbon was very laborious, so next time I'm gonna consider doing the walnut blasting if I can find cheap enough machine or rent one.

 

^^ it's the air compressor that can meet the air volume demands that cost the most. You need a lot of CFM to be effective for the baked on chunks. Yes there is downtime to spin the engine, clean up, seal ports, I can only imagine this is 10X faster than any chemical process.

 

I found this 110 lb. Pressurized Abrasive Blaster from Harbor Freight for only $160.
It took me an average of 30 minutes per valve x 12 valves,
it took a long time and I had to rest after each valve as my back was killing me.

Definitely, such machine can speed up the processing by more than 10 times.

https://www.harborfreight.com/110-lb...caAhYVEALw_wcB

If anyone is in Houston area, we can collaborate and share the machine.

 

If you consistently run seafoam into the brake booster tube the way I describe, you will eventually get all of it without having to scratch any of it off. It will not work in the fuel tank. It somewhat works as an oil additive, but only as fast as it can be carried by oil vapors to the intake valves.

I know this for a fact because on our 2.5L engine, I bent and hammered up a bunch of coat hangers like they taught us to do for weapons maintenance on Ft. Benning, scratched each of the valves clean using methyl ethyl ketone to soften the carbon up, then repeated the time consuming process every time my wife needed any kind of maintenance as she daily drove it. I even tried soda blasting it myself when MEK got difficult to buy over the counter. I started the seafoam process as a "yeah, whatever, I took care of it again" response to my wife's suggestion that it needs attention again, and has worked for me since. At some point I put an oil catch can on, before I started seafoaming

The 3.0L in the car right now has never had anything but seafoam fed into the intake via the brake booster hose and it's clean enough inside for me to not feel the need to borescope it anymore, although I'll pop it open and take a quick pic if you really, really want me to. It showed up just as carbon caked as any of the cylinder heads on my bench did. Matter of fact, I can do a side-by side of an untouched head as it showed up from LKQ and the head that's in the car. The 3.0L has never had a catch can, even though I tell everyone that they're good ideas on the 3GR and 4GR.

But you know what? you're right. Mindless consumption is the only way. Surely the whole thing is garbage.

Now inasfar as the cold start injector being used to help keep carbon at bay: I was hoping to find the spare cold start I have, but it's buried under a pile of other stuff somewhere now, so I can't prove my point just yet, but the injector itself actually has a spray pattern to it. IIRC, it's three slits per side. While I wouldn't say it does as good a job as a carburetor as atomizing fuel, I daresay it could run the engine by itself--albeit poorly--like a first-generation throttle body injection engine. It's fed by a banjo bolt that goes to a hose fed by the pressure overflow coming off of the high pressure fuel pump, which I assume it's going to be around 50psi. I know the direct injectors are 2.2ohm, and I thiiink the cold start injector tested the same, but that was long enough ago for me to want to retest the cold start as soon as I find it. I think the risk of using the cold start injector in a way it wasn't intended is overheating it through too much use, since it's just a 2-wire solenoid and it'll be feeding fairly hot fuel coming off the HPFP...whether it's hot enough to allow the solenoid to fail is to be found out.

 

Nice to see CowBoE here, I watched your video thanks for help!
There is study crabon collection is mainly at 200-300C, so port injection cold down the valve helps also. If this is correct then make use of cold start inject occasionally won't help that much, unless we can use it as port injection style, not sure ECU allows us to do so but if needed I can build microcontroller to do so.

I watched Harbor ,Pressurized Abrasive Blaster, it seems just a air tank no particles used right? do you aware any commercial walnut particle sprayer product or service?

I forgot most fuel alignment so not quite understand other post, Mike would you mind to explain a bit: problem, expected, and solution?

Oil catch up tank installation and effectiveness: I thought near bottom there would be a manual valve, like this expensive model: S1-OCC

 

I'm not sure if the question is about the catch can, or carbon? or if it's even directed to me.