2008 Clubman "Carbon on Valves"?

[andyleonard]

CEL on at 30K with a sudden miss at idle, dealer says "carbon on intake valves." Walnut shells were on the warranty receipt. I asked if it had carboned up like a 1952 MG because of something I did...and the SA said "no, it's Mini."
Someone please explain what's up. This one was free (warranty) but the next one won't be. Is this an oil issue, a fuel treatment issue, a seal issue? I'm clueless. Thanks.

[jbz]

The PCV system on the 2011 MCS has been changed to prevent carbon on the intake valves. Maybe it will just delay the problem ? Only time will tell if it is better.

Search on this forum on how to modify your PCV to be effectively the same. Some Peugeot parts are used. Sounds like a cheap and easy job.

[marque]

Hi ya

Like jbz says it the positive crank case ventilation system causing it,
Hot oil mist is draw through the inlet track and then comes in contact with the hot inlet valve and starts to burn on to it. soon as it start to build up, it will carbon up quicker as the temp gets hotter from the carbon and the build up is bigger and so the problem gets worse
A lot of guys I know run a catch tank and bypass it all so it stops the carbon problem.
And they also run BG44k fuel system cleaner though the system and so far we have done visual checks on the inlets and they seem toe be in good condition after 12k

[andyleonard]

O.K. Got it. I'll reroute the breather into a puke tank...just like the racecar.

But what the hell were they doing with walnut shells? We use walnut shells in the blast cabinet for aluminum polishing, but wouldn't running them through the engine clog the cat or something bad?

[marque]

Hi

We used to throw a hand full though the aircraft engines to clean the compressors when they were really bad.
The walnut shell should burn away. But it's abit exstream to shove then though the inlet track I would not of thought it was a good idea.
If the carbon is really bad the only thing to do is remove the head and do the job properly.
I have seen some threads where people remove the inlet manifold and clean there inlet valves. making shore the valves are closed on the cylinder there cleaning then using a Shop vac to hover the crap out then cleaning using bottle brushes, scrappers and flushing with carb cleaner. Then run a 3 step BG cleaning kit.

[andyleonard]

Here's the language from the service order (direct copy/punctuation is theirs):

Installed MINI428376 : cleaner MINI warr unit Qty:1 Performed test plan B1214 inspected carbon level s of intake valves they were level 5 cleaned all intake valves and update DME per test plan diag code D1110 B0000000 20 306 programming validation coded1214 B0000000 90 210 sublet walnut shells


I'm pretending to not be stupid here...what did they do? They still have the car.

[marque]

Hi

the only thing i think they could have done is remove the inlet manifold, and make shore the cylinder that there working valves are closed and basically shoot blast the valves using walnut shell then clean and flush and hoover them out, then move on the the next one.
but thats only a guess

[andyleonard]

That's what they did. Blast and vacuum. They have a new machine for it...there's a thread on NAM about it. The car went from 23mpg to 29mpg immediately and feels like it has about 20% more power. It took 4 years to clog up, so I didn't really notice, but what a difference when they cleaned it. A low speed hesitation went away at the same time and of course the CEL went out. I guess if I don't put the puke tank on, there's still a Seafoam process they suggest. Stupid design.

[dsakko]

There's a new product on the market from Wynn's. Wish I could find the link now. You run the motor at 3k rpm with the air filter removed and spray a can of powdery stuff down the inlet. Use every service or every 2nd service. They say it's starting to be a common problem with DI gasoline engines.

Supposed to be safe for turbos too.

[Angib]

There's nothing new, is there?

Walnut shells are/were the preferred method for serious cleaning of gas turbines - the shells clean the compressor section but have completely burnt up by the time they reach the combustion area. For warships, a bloke with a barrel of crushed shells and a shovel would hoi them into the air intakes - comic but effective.

[dsakko]

And Boeing used to have frozen chickens on their parts list to be thawed and used for bird strike tests