2nd Gen R56 Cooper S Most liked posts in thread: The 'Carbon' Problem...

Pic's from M/T
R56S valves at 27k


R56S valves at 58k (one after cleaning)


Comments;
The 27k car had slight hesitation with half throttle acceleration, while the 58k had a massive flat spot and major hesitation with all throttle positions.

 

From what I understand the main carbon build up seems to be on the back of the intake valves. Running Techron through will certainly help the combustion chamber & piston top stay clean, but I can't see how it would be able to clean the back of the intake valves. Being direct injection the fuel/Techron does not go past the intake valve.

Looks like the MINI version of the Italian tune up is to drive it until completely warm.

Rather disturbing that MINI does not recognize this as their problem.

 

Das German Enkineering Roomin

Yah..... Hinerich, das esn Peugeot's kerlunkinfukin, nict esn BMW/MINI (much German laughter in the background)

 

That reminds me...
Das German Coastguard
[ame=http://www.youtube.com/watch?v=gh5xu35bAxA]YouTube - FUNNY! SOS! MAYDAY! SINKING![/ame]

 

So it seems it's a progressive thing (obviously). The wet becomes completely chemically un-reactive with the operating temperature at the point where the valves are located. The oil laden fumes are constantly bathing the valves with the "wet" solution (PCV system). The Seafoam doesn't touch the completely chemically un-reactive carbon buildup (or very little). So the Seafoam only addresses the wet and only at the time of application. As soon as the engine is started after a Seafoam treatment, the process starts immediately again and continues until the next treatment, but only for the wet contition. If the Seafoam isn't constantly being applied, the carbon buildup wins. The addition of the oil catch can have the ability to stop the carbon buildup if it's 100% effective (which they aren't). So the best we can hope for is a slowing down of the carbon problem with a OCC.

Or the physical removal of the un-reactive carbon buildup with the current BMW/MINI "walnut" method (expensive). And this method is also just temporary but addresses the chunky carbon buildup completely at the time of treatment.

OR become a traveling salesman that does a lot of interstate highway traveling versus the short run stop and go pattern that speeds up the buildup.

For the Seafoam to really work it would need to be constantly applied to remove the "wet" before it becomes chemically un-reactive..... I'm not convinced the Seafoam really offers much. The only argument there is would be if you didn't do a treatment the wet it would remove would eventually become the hard carbon.

Seems like the best thing to do would be to install the most effective OCC there is ???? and do the walnut method when required.

Your mileage may vary.

 

The Techron will help keep the injectors clean along with the combustion chambers. It is not going to do a thing for the intake valves due to your MINI being direct injection.

 

Check this article out. It's a fantastic breakdown of DI and how the carbon buildup affects cars. Sounds like early DI engines are particularly sensitive, before they figured out how to re-route PCV valves and EGS lines and alter the combustion. Case study is an RS4 that loses 1 hp every 500 miles.

Direct Injection Fouls Some Early Adopters - AutoObserver

 

I think MM is going to hire these guys

 

So that's how they make the walnut chips..... I was wondering how they did it....

 

Yep, got the pickup tube a week or so ago... Real nice German aluminum casting with multiple step vacuum attachment fitting. The small hole is for the high pressure wand that shoots the crushed walnut shells at the carbon buildup.






I haven't had time to build the rest of the system. Need to make a pressure pot and Harbor Freight sells the walnut chips in two different grits.

 

I'm guessing that wasn't a justa. :lol:

Jim

 

^^^rrr:rrr:rrr:

 

Once I'm done with the warrenty, I will be doing that. I also have the BSH OCC, but not their boost-tap (well I actually do have that, but it's somewhere in my basement). I just wish there was a dual-OCC option

 

OK..OK I read most of this... BUT.. IF you dont go to the chemical... are the Head being removed and then dis assembled and the carbon cleaned?? Is this what a lot are getting done??

Just aSKING.................

Thumper

 

If chemical.... Do you mean the Seafoam or similar method???? That doesn't seem to touch the "baked on" hard carbon buildup on the valves. If it's under warranty and the dealer has the "walnut" kit, the lower cost, quicker method is the walnut blast with the head left on the engine. Seems to be a two hour or so job to perform. The pulling of the head requires more labor which equates to more expense. Especially if a replacement head gasket, head bolts antifreeze etc, etc, etc, gets replaced.
The pulling of the head would allow all the carbon to be removed. The walnut method probably leaves a very small amount around the edge of the valves and maybe directly behind the valve stem, since the wand and the walnut particle size limits 100% removal. Boils down to a cost trade off.
What is not totally clear..... BMW/MINI has progressively improved the design of the PCV system. Are any of these improvements having any noticeable reduction in carbon buildup?
For the average R56S owner.... I suspect the "walnut" method, with leaving the head intact, will suffice.....

 

Any engine problems with the R56 also apply to the R55.

Dave