No, it's only n14 gen 2 Turbo cars that have the issue the worst.

 

I have a 2014 MCS Roadster with 19,000 miles and have consistently averaged between 33 and 37 mpg indicated by the ECU. Most of my driving is highway miles, though, since my car is a daily driver and I commute 30 miles each way. When I drive in the city or when I am enjoying more spirited driving, my mileage drops considerably. Mileage depends on the type of driving you do. Carbon build up, which is the topic of this thread, might have some impact on mileage, but I don't think it is the major factor.

 

2013 turbo roadster to 2004 supercharged coupe is apples to oranges. But that is awesome mpg. I agree that a significant factor for mpg is the type of driving you do, but it is only one factor. Are you getting a range by resetting your mpg average? A 4mpg change is a pretty serious change in fuel efficiency. I am actually more curious about your actual MPG calculated the old school way.

Carbon build up could have a fairly significant impact on fuel economy as well, I would think. If you go back to the pictures posted on the first page of the thread, you know the original topic, it looks to me like those sludge encrusted valves may have a bit of difficulty sealing to the valve seats and an even greater likelihood of being "sticky." Multiply that by 8 to account for all of the intake valves and that may lead to a fair loss of compression not to mention a host of other potential problems. But there is an easy way to find out, let's ask the gent that posted the pics whether he experienced a reduction in fuel efficiency.

 

I generally reset the avg mpg every time I fill up. I've calculated my mileage the old way and it's usually somewhat less, maybe 0.5 to 1.0 mpg less. The old method can vary somewhat from tank to tank depending on when the pump's automatic shut off kicks in. The shut off point can be different from one pump to another. My lower ECU readings were generally in the winter or when I drive more aggressively. On a 120 mile St. Louis MINI Club rally, I think the ECU showed around 25 mpg but I was doing a lot of downshifting and hard acceleration and there were lots of hills and twisties on the route.

 

Count me in ..

2007 MCS with 55k sitting at the dealership now for issues due to carbon build-up. Orlando MINI is charging me $450 for the blasting, and because they consider it to be a "maintenance item" it falls outside of the best extended warranty I have on the vehicle. To be honest, I am livid. I bought the car on 9/8/13 as a birthday present to myself. I knew buying a MINI would come with issues, but I was NOT expecting MINI to leave me hanging due to issues that are notoriously common and even MINI tells me, is due to a poor design on the vehicle.

Way to leave a sour taste in my mouth, MINI ..

 

Is this the same dealer you bought it from? I would be absolutely livid. One month after you bought it? If it's "maintenance" it should have been done pre-sale. And if it's not in your manual's maintenance schedule, then it isn't maintenance, it's a repair.

Good luck. Sorry it sucks. :-(

 

If I were you I'd absolutely refuse to pay for the walnut blasting. This is a known issue and since you just bought the car a couple of months ago it means the problem was pre-existing.

 

Unfortunately it is not the same dealer .. I bought the car from a local Nissan dealership, but obviously I don't want them working on the MINI. Because MINI considers it "maintenance" due to their garbage design, even my extended warranty won't cover the blasting. The car has been sitting parked for a week undriven because the issues this build-up is causing is just getting worse and worse. Only drove it to get it to the dealership (short drive).

Sadly, even the Service manager admitted to it being a notorious issue in the "S" models, whereas most other direct-injected vehicles wouldn't experience carbon build-up related issues until they reach higher mileage. Not MINI though, it's happening in MINI's much newer with a lot less mileage.

They don't care though. They acknowledge the issue is due to a flaw in design on MINI's end, but there is still nothing they will do about it. I took the issue up with both Orlando MINI, MINI USA, and NISSAN NA (since they hold my warranty) and no one wants to take responsibility. This IS NOT typical "maintenance" and the fact that MINI is weaseling their way out of taking responsibility for their poor design by calling it such, is absolutely maddening.

They also made it a point to blame Nissan for having sold the car to me, that they should have known by the hesitation that something was wrong? Right .. they should have known, especially if Nissan primarily deal with Nissan's all day? What a joke. I don't blame Nissan one bit.


Forgot to mention, Orlando MINI hasn't done the blasting yet .. my car is just sitting there until I figure out what to do with it. In other words I either A, choke up the cost or B, continue to drive it until something worse happens due to the build-up. They pretty much force you into paying for it .. because if you continue to drive it and something worse happens, they can call it "maintenance negligence" and you're stuck coughing up even MORE money.

Bunch'a bull if you ask me.

 

gee my 04 mini not the S has 94K miles on it with no problems with carbon so far and i sometimes use 89 octane when im feeling cheap i better not do that anymore have fun

 

I have a 2007 MCS 50,549, I was having pre-ignition/misfiring badly at 49k! Count yourself lucky because I paid twice what your dealer is asking, just remember to get the walnut blasting done every 35-50k. I found a place 60 miles north of me that only charges $350 for walnut blasting. In the end I paid $800 for my dealer (Irvine/Newport Beach area!) to blast my valves, what a night and day difference!!

 

Any you won't ever... its an older style injection system.

 

So this brings up an interesting question then ..

.. if MINI USA is classifying this carbon cleaning as a "maintenance item" and not a defect in parts or workmanship SOMEWHERE under the hood .. and because it's "maintenance" they will not cover it .. then why is it not in our maintenance schedules or manuals? .. and if not in our maintenance schedules, then why are we liable for such "maintenance upkeep" if MINI doesn't provide us with the information to even know that this should ever be done regularly? Maybe it's common sense and we're supposed to know all about direct-injection and carbon build-up before buying a car? Well shoot, call me an idiot then.

I mean .. if this build-up is "normal" for the "S" models and should be maintained the same way you maintain your oil or brakes, then why would MINI not prompt us to have it done at X miles like with any other service? .. and if it's not mentioned in our maintenance schedules, then how is it not covered under anyone's extended warranty when it does eventually cause issues that could do some serious damage if left unrepaired?

When I bought my MINI, I definitely took in mind normal maintenance repairs such as belts, brakes, oil, etc. What I didn't consider, was a walnut blasting for excessive carbon build-up that while "normal" for MINI's, is not actually normal from any other manufacturer will direct-injection vehicles. I am still very upset about this.

 

It's not just Mini that uses direct injection and all direct injection will have the same issue unless manufactures somehow trap the oil before entering the engine. If it was port injection this thread wouldn't exist, I just think manufactures will eventually get this right. Look at it from a business standpoint, holy cow are they raking in the money!

 

I'm truly curious if the manufacturer would even want to actually try to somehow prevent the buildup. But I think there's a reason that no car brand company has come out with it so the government makes more money by cleaning the valves that provide jobs for the economy.

I wish they could find a fix for it so if I did buy another DI car then it wouldn't be such a drag to pay $350-600 for the walnut blast.

 

You are absolutely right, but MINI definitely lacks in terms of direct-injection technology that doesn't have issues at incredibly low mileage. I've been lurking these build-up related threads now for a while, and I'm seeing a ridiculous trend of newer MINI's with much less mileage than mine (ex. 2012 with 20k) having these build-up issues.

I am practically backed into a corner on this one and they force you to choke up the cost of blasting. Because they call it maintenance, not doing the blasting could put you at risk for being considered "maintenance negligent" when worse issues arise. Well, as much as I'm complaining about the $450 now, I'm sure I'll love my car even more when it's done.

 

I would suggest taking the owner's manual in with you, and asking them to point to where in the maintenance section it says that the intake should be cleaned.

 

Someone else mentioned that too, but I feel like it'd be beating a dead horse at that point. MINI has clearly made their stance on it obvious.

 

Generally I hate the litigious nature of our society, but this sounds like it might be a good reason for a class action suit.

 

Wouldn't that be something. I bet if MINI actually looked at the statistics of their vehicles that encounter issues due to this carbon build-up, they'd be surprised. Although at this time, we already know they are well aware of the issues and simply don't care.

I forgot which thread it was on in this forum, but someone with a 2012 Cooper S with ONLY 6000 miles, had to have this car walnut blasted for related symptoms. C'mon MINI, really?

 

Bit the bullet and gave the green light for the walnut blasting. I have to, I need my car. Car should be completed by Tuesday, they want to keep the car an extra day for testing. G*d help this dealership if this does not solve the issues I have been having.

 

My dealer denied any knowledge of heat issue melting scoops, even after I gave the part number for the shield that they had in stock. Got one for my CPO 2011 as well. They should never have stopped installing at factory.

 

2007 mcs 55k miles

Walnut shell cleaning at Pleasanton ca mini dealership. $800

 

Finally picked up my 07 MCS today from Orlando MINI. Paid $395 for the walnut blast. The car definitely runs a lot smoother, and I am loving it. Very pleased with the results.

 

2007 MCS

72000, Had walnut shell blasting done (as well as way too many other things to list here)

88000...drivng back from airport and nice little yellow engine-shaped light comes on the cluster...runs like hell, codes say "misfire on Cyl1" and "misfire on Cyl3" as well as "random misfire".

2 cylinders wasn't enough to drive 4 miles to dealer...so had it towed. I'm assuming (at this stage, hoping) that it has carbon buildup.

I'm creating the list to build my own walnut shell cleaning setup now. With all the uncertainties...one thing I AM CERTAIN about is I will have to pay for the results of MINI's DI design.

 

Sounds like my symptoms when the high pressure fuel pump failed.