I think the larger problem with seafoam, etc. is in sending that carbon debris through the turbo. You can easily damage a vane that way and if that in itself doesn't kill the turbo, the resulting imbalance will kill it soon enough.

I also suspect the problem is not so much with oil instantaneously burning onto the valve, but rather oil sitting on the valve for some time, becoming too viscous to be blown off by airflow, and then eventually baking onto it over multiple heat cycles. It may also be that you get more blow by on cold startups, which needs an extended operation to clean off. That is, short drives at lower engine temps may well leave more oil on the valve which then builds up.

It would be no surprise to me if this is showing up on Explorers first, since they're the family workhorse. Crank it, drive it to the store, let it sit; crank it, head to the cleaners, let it sit; crank it, go to soccer practice, let it sit...

Until Ford offers better advice, the best preventative, imo, is a good synthetic oil.

 

Okay I'm going to avoid starting another oil thread here, but there doesn't appear to be a causal remedy or solution to behind valve build up by running any particular type (or brand) of motor oil. And to be fair to Ford, this isn't just a Ecoboost issue, but has become apparent for GM's smaller DI Ecotech engines also. The combustion byproducts need to go somewhere that satisfies emission requirements.

 

Good evidence of this would be if any of the police explorers seem to do better than the civilian explorers, as though are running most of the day. Then again, I'm guessing most departments are not opting for the twin turbos (ours didn't, unfortunately)

 

^This. It is a problem for the DI Cadillac 3.0 and 3.6L engines, the VW / Audi turbo engines, BMW engines, and basically everyone except Toyota that uses DI. I think oil has nothing to do with this problem.

The solution "has" to be a chemical cleaning, though. It's just way too expensive to require a head removal as part of standard maintenance at 60 or 100k miles.

 

One person on the Pontiac Solstice Forum posted a good idea which he even posted photos of the procedure.. walnut blasting. He removed the intake manifold and using a portable sand blaster, used walnut shells to clean the intake port and valve on the intake port used for crankcase ventilation. Even though when done blasting he blew out the runner and cylinder with compressed air, any shell particles left over would just be burned in the combustion process. I think this would be a faster and more thorough process than solvents.

Scroll down in the discussion and you'll see the process and results. Pretty impressive: http://www.solsticeforum.com/forum/f...le-vid-108817/

 

I like this idea. Removing the intake is a lot easier than the head(s). But, you would need to make sure the intake valves were closed, or you would be filling up your cylinders. I can only imagine though, what these guys will say to burnt walnut casings going through the turbos, which are apparently so fragile you can't so much as look at them wrong without bearings failing, seals, leaking, and vanes breaking.

 

They will say go right ahead - it's your car, and your pocketbook.

 

I read with variable valve timing the engine management software can adjust the valve timing enough to allow gas to rinse the valves. I think the EcoBoost would make a great addition to the Super Duty line of engine choices.

 

But in a Direct Injected engine, the fuel isn't sprayed behind the valves, but directly into the cylinder. How would changing the valve timing get fuel on the back of the valves? Doing what you suggest would mean a LOT of fuel would need to be sprayed into the cylinder, probably causing a hydro-lock situation before ever rinsing the back of the intake valves.

 

It's been speculated that the next ecoboost will have two injectors per cylinder to ensure that the valves are washed with gasoline.

 

If I had an Ecoboost engine with carbon buildup, I would be getting it walnut blasted before replacing the heads.

If BMW approves of this, it's absolutely not going to hurt an EcoBoost engine:

 

You are correct, and I think BMW even supplies the machine.

The thing about the walnut method is that as far as I know, it requires the valves have to be closed so the shells don't get into the cylinder (so they can't be passed on into the turbo). If so, then there's a caveat - you can't clean the valve seat. And if you're experiencing misfires due to the valve not closing, then there's probably carbon build up on the seat itself, which means that either it doesn't get cleaned or you can't actually do the service since you can't get the valve closed completely. At least that's the way I see it.

Now, I've heard of people using dry ice instead. With that, you could open the valves during cleaning since any ice that got in the cylinder just evaporates. That's a solution I'd be more inclined to accept, but of course you still have to worry about bits of carbon debris. Maybe a two-step process where you clean most of the gunk with the valves closed, then wash out the intake and do a second round with the valves open?

I don't know - it seems like one of those things where 99% of the people who did it would have no problem at all, but then there's that unlucky 1% or so who end up with a walnut shell jammed in their turbo.

 

I've heard Toyota has been looking at that idea, but having a second injector negates the advantages of DI, plus adds more parts to maintain and control with engine management systems. The idea of adding an injector to occasionally wash the back of the valves as a cleaning method reminds me of something similar with burning off DPFs in Powerstroke Diesels. A good idea on paper, but that's about it.

 

Here's another good description of the process: REVIEW: Cleaning of intake valves with BMW walnut shell blasting tool

 

Toyota is already doing this with their D4-S and has been for some time. The second injector is in the traditional intake port location. It only works while the engine is cold and / or when the engine is at low RPMs. It works in tandem with the direct injector. At higher RPMs, only the direct injector is running. Engine management controls both, so when both injectors are working together, the pulses are shorter and timed - no extra fuel is used. The advantage of this system is allegedly a more stable engine speed control and lower emissions...but I would say the big winner is not having to deal with carbon build up on the back on the intake valves. Of course the downside would be the extra cost of a secondary fuel rail, plumbing, injectors, and a little extra CPU programming. But none of the advantages of direct injection are lost.