I'm new to this forum and joined to find out more about the problem we are having with our 2008 Clubman S. It has been to the dealership 3 times in 6 weeks for excessive carbon build up. It was misfiring in cylinders 3 and 4. They removed the intake manifold and cleaned the intake valves.

From what I have read on this forum, Mini knows of this problem. Our car is under warranty, but I see that off warranty cleaning of the intake valves is very expensive. Are there any DIY fixes?

 

Do you do any "Italian tuneups"? http://en.wikipedia.org/wiki/Italian_tuneup

 

Search for Seafoam treatments and also catch cans to intercept vapors before they get to the intake. Catch cans = $ but I have one and am very happy I do. Good luck.

 

+1 the Seafoam. Somewhere around here is the procedure for Seafoaming through the PCV - that's the one you want. Everyone I know who's done it swears by it. I haven't yet, but I'm coming up on 10K, so I'm due.

The problem is inherent in a lot of early direct-injection motors. MINI definitely knows about it, because they addressed it starting with the 2011's.

Ahh ... here's one of the links.

 

I like the Italian tuneup, being as I am Italian. I realized we don't use the Mini except around town and I don't drive it as aggressively as our other two cars, a Vette and a Porsche.

Seafoam sounds like a common treatment. I am a bit concerned about statements from those that call it "snake oil". But a lot of members of this forum swear by it.

We are planning on selling the 08 Clubman S and getting an 11 Countryman S. If Mini has dealt with this carbon issue, we may stay with that plan since we really have loved the Clubman. Otherwise, we will look at Audi A3s.

 

You will find that since the introduction of the N14/B16 engine, the 11/2005 -11/2008 had a poor design of the PCV system, and the models with the this early cam cover, suffer more from excessive carbon build up.

The revised cam cover was introduced into the factory line from 11/2008 to 03/2010 for the S model, when the introduction of the new engine arrived for the S model.

So for those of you that don't want to fit a catch can, then you have the choice of fitting a later style 11/2008 - 03/2010 cam cover, and this has better PCV control.

Sadly the JCW model has not received this new engine yet, and so is still subject to carbon build up, but fitted with the latest 11/2008 onwards, revised cam cover for better PCV control.

 

Carbon build-up is a common problem with direct injection. The fuel is not going by the valves during normal combustion and regularly washing off the products of combustion like older cars. It seems some companies have had more success than others and MINI is not alone with this issue.
Seafoam is one of the better solutions I have read about. I have done the intake cleaning on my R53 with great results (or at least big clouds of black smoke).

 

Carbon buildup seems to be an issue on all "early" direct injection engines. The A3 you are considering as an alternative has a similar engine to the MINI's, I suspect they're talking about this on their forums too. An anecdote that my dealer friend told me was that the ones they've seen with the problem are cars that see only light duty, i.e. short commutes and never revved up much.

 

It's not just an around-town problem, my wife's 08 Clubman S gets 100 mile round trips almost daily with a lot of highway, but it's driven pretty hard the rest of the time too. The dealer just did the cleaning at barely under 50k (still under warranty) but I'm damned if I want to pay for or do extra maintenance on what is in today's world a fairly low mileage car (that has had more than its share of other issues as well). I have written to MINI to complain, and I hope anyone else with similar problems will also. Maybe they'll come up with a fix, or at least arrange for an extended warranty covering this problem.
I've heard that the ethanol in today's gas is part of the problem. Any thoughts on that?
Decoking the cylinder head every 40,000 miles is SO 50's.
Mike
'08 Clubman S (wife's car)
'67 Austin Cooper S (my car)

 

It is an engine design flaw. Our 08 Clubman S was running badly and the check engine light came on. Went to dealer 3 times before they decided it was a carbon problem. Service rep acted as though it was our fault and denied that Mini knew about the problem. We use top tier gas and drive it pretty hard on occasion, but it is our around town car. We have otherwise loved our Mini, but we are now considering something different. Our warranty runs out soon and I don't want to pay in excess of $800 to get the carbon cleaned out. I have begun putting a bottle of Techron in once a month and that seems to be helping. The car does seem to run better.

 

Even with a revised cam cover, the amount of bi-product caught by the catch can is astounding. To think that this volume of product would be recirculated to the intake tract, I could see why problems might occur so early on. My recommendation to anybody who plans on keeping the car for any extended period of time - purchase a catch can. I have the BSH catch and really like for a number of reasons.

 

So, how often does one have to empty the catch can?

 

Depends on the size of your catch can, but with proper tube routing you can expect about half a gallon in 3,000 miles:


https://www.northamericanmotoring.co...n-install.html

 

But havn't you basically built a stile and by design now it will produce moister? So you are getting a a lot more liquid than if it was using the stock set up. Don't get me wrong I see how it would help with the build up but the amount of liquid I think is increased because of the collection process. Anyone else?

 

The purpose of the extra tubing is to remove as much heat from the vapor as possible in order to promote condensation. I can only assume I'm catching a very high percentage of the crankcase vapors. It looks like half of the liquid in that bottle is oil.

The amount of vapor exiting the valve cover will be same, regardless of what catch can system you use.

 

I did the carbon clean up under warranty at 39K. I also brought my car in on a separate occassion for rough starting after the 39K. I've also religiously used Chevron 93 Octane. My car threw the same fault code today at 59K.

I am brining it back to Niello Mini, and as long as my fault code is the same at 39K, they take it up to next level which is to do the cleaning, and install a new high pressure fuel pump. They have to get approval from MINI first, but if they do then all of costs are covered by the warranty of the Fuel Pump. I may have to pay for 50% of the diagnois, but that's it. I have to wait till the 7th as they are super busy. I wonder why?

In any case, the my MSA says this is a known problem by them and MINI. I'm hoping a permanent fix is out there.