Walnut Shells for Cleaning Intake Ports on DI Engines?

If cleaned right after blasting??

 

Some test's state it propagates under the surface even after neutralized. Failure has been found on aluminum wheels.

I would personally stay away from it to be safe.

Use the softest least abrasive media to do the job.

Dry ice is really trick but big $$$ for a good setup. We have a few guys here with 30 foot trailers that do on site for mainly fire restoration on wood frames. They will do anything you ask

 

Pro's have discovered that simple walnut shells meet all criteria for getting the job done safely, effectively, and cheaply. In fact so much so that even a Stooge can do it and buy all necessary equipment from "Snap-on for stooges" aka "Harbor freight and tool".

 

Maybach: CH-47 Crash in Mannheim, Germany

I am sure the military has strict procedures using walnut media I wouldn't trust it anywhere near a expensive motor, maybe it's safe but when I put my foot to the floor hit 9000 rpm I want total confidence in the motor

 

Totally different application and if you read the article safe before there was a shell removal change due to occupational safety concerns. I am sure the engineers who came up with the previously safe process were alerted to the need for a change by their OSHA type beauractrats. Sounds more like an indidictment of "unintended consequences" of a good idea typical to our world today.

Sorry but that article is like making love under an oak tree and geeting one's girlfriend pregnant and blaming it on the Oak tree.

 

You are correct. OEM is or is about to recommend this as a procedure, BMW I believe then a pressure flush to clean off the valve seats. German cars seem to be suffering the worst. I have a few different pressure blasters if you dont want to mess your driveway, here in the ghetto we do it all the time

As to military applications, they are usually about 10-15 years behind in maintenance procedures. Like the FDA LOL

 

Is there a reason to use dry ice over water ice for blasting? I thought the former is used for materials that can't tolerate a little water/liquid on them while the latter can. Would cleaning the internals with water ice and then drying before using the car be okay? It's a lot less expensive and also a non-abrasive cleaner.

 

Right up my alley ...

 

I have heard of water ice blasting but its never really taken off, when dry ice pellets hit the surface they vaporize into the air leaving no residue, all thats left when dry ice blasting is the substrate material.

 

Dry Ice cleaning was first used by the Army and Air Force in 1945, the mid 80s Cold Jet patented and came out with a commercial machine.

Dry Ice Blast Cleaning | Dry Ice Blasting


As for the OP question on a $30000 plus Ferrari engine would suck to blow it up with .02 cents of Walnut Shell Media clogging up one of the tiny oil galleys lol.

 

Wow dude, those are frickin nasty!!!

 

Any media making its way into the crankcase would have to pass through the suction pump screen (I doubt it's hard enough to damage the pump if it got past) and then past the oil filter which is essentially impossible unless the filter is damaged.

 

I feel I need to clarify the above statement. In regards to the direct valve cleaning influence of various fuels and additives, yes, it is true they have little affect due to the reason stated. However, with respect to a specific fuel's ability to keep injectors clean does have an affect on intake valve deposits. With DI, the most important and most intricate part of the injector is exposed to the combustion process, just like the spark plug. The extremely tiny spray pattern/atomization holes and valve/seat can get carbon deposit buildup and cause misfire or fuel leaking after the engine is turned off. Both conditions lead to raw fuel passing the rings and mixing with the engine oil making the oil more volatile. The more volatile portions of oil tend to easily vaporize and make their way into the intake manifold via the oil tank ventilation system. It is these highly oil enriched volatiles that get deposited on the backside of the intake valves and ports that will eventually cook and harden into the gunk shown in this link.

In most cases, unless the injector is really bad the engine will seem to run fine and no CEL will appear. That's what makes the condition difficult to diagnose and why the same model car can show such different amounts of intake valve buildup. Of course, driving conditions (lots of short trips) also plays a big part.

Bottom line, run good gas to keep your injectors clean and change your oil more frequently to remove any volatiles. This will reduce but not eliminate the problem. But eventually, with enough miles you'll probably need to manually clean your intake valves just like I did.

 

I had the same issue when I removed the Intake Manifold on my 6.3L V8 Mercedes E63 but instead of dealing with mess of going the walnut shell route (as the Intake Runners on mine we’re not a fit for the Dual Function BMW Adapter which connects to both a Vacuum Cleaner and the Air Compressor holding the Walnut Shells) I opted to remove both Heads and have them rebuilt! Mind you, these heads have overhead cams too but the Cam Adjusters, instead of the timing chain running around each, have a Drive Sprocket below them to which the timing chain engages from below. This makes removal of the Cams, and by extension the Heads, an easier affair as you don’t have to remove the timing chain! It’s a good thing I removed the Heads too as I had 8 of 16 Intake Valves which were bent that I otherwise would never have realized were there.

As for a Catch Can, I ran 1” Heater Hose from the Crank Case to the Catch Can out to the PVC Valve connected to the Intake. I empty/clean it with Brakeclean every Oil Change. I ended up using one I saw in one of those Specialty Shops for Mopar Cars. There were several to choose from and I chose the smallest measuring about 3” in Diameter to stash behind my Headlight! It works like a charm as my Intake that was previously coated with oil prior, is now bone dry! So no, it’s not a sham idea for if the blow-by oil is reduced so much as to keep the Intake Bone Dry, the less likely that oil laiden blow-by air will coat the intake runners.