The check engine light came on yesterday. I brought my mini to the dealer, but staff there were too busy to do anything on this poor thing today. The staff asked me to leave my car there for four days. But I cannot do that since I only have this one car.

I insisted that they at least check the code. The guy took a few minutes and quickly check the code and told me it was "misfire." He speculated that the misfire can be due to carbon buildup. As he specified, the fact that I have never driven the car hard enough and I have never driven the car at the sports mode can lead to carbon buildup. He turned off the check engine light and poured a bottle of mini fuel cleaner into the gas tank. He asked me to call him and make an appointment with him when the light comes on again.

He estimated that if they have to do some manual cleaning, it will cost $1200. Oh, my god.

The guy said I have been babying my mini since I only drove 8.5k in the past four year and never drove it in the sports mode.

Any similar experience here?

Below is the basic history of my mini:
2009/09: I got my new mini cooper s 2009.
2012/08: check engine light came on with the mileage of around 6k. The dealer checked and replaced the high pressure pump.
2013/06: check engine light came on again with the mileage of around 8K.

 

Do I understand you correctly, carbon build up after only 8k miles? That's got to be some sort of record.

 

I'd be worried if your SA thought pouring fuel cleaner in the gas tank is going to do anything for the carbon buildup.

There is a school of thought that running the MCS too easy on short trips accelerates the carbon buildup problem as things never get warmed up enough to help it burn off properly.

Use of the sport mode button is not relevant to the carbon buildup.

 

Thank you for your reply.

The dealer asked me to bring the car back to them when the light comes on again for a thorough check. I wonder whether such waiting can lead to more serious problems.

 

Thank for your sarcasm.

The staff suggested that in order to drive my car harder, I drive it in the sports mode when I am driving on local roads.

His suggestion again is built upon his assumption that carbon buildup as one dominant reason for misfire. He did not inform me other possible reasons for misfire.

One thing I just realize is that the last oil change was done in March 2012. I made an appointment for the oil change service this coming Wednesday. I am not sure whether this can lead to misfire. Note that I drove my car only for 2.5k miles since March 2012. How often do you guys change oil?

 

Fuel injection cleaner will do NOTHING for a direct injected motor. Also $1200.00 for a carbon cleaning should be some type of record. LMAO. If he is correct and there is carbon build up in that low of miles I would be concerned about the damage that can happen if you continue to drive it without the cleaning. You can and will damage the engine if it is not done. Ask them for a loaner car and then you can leave it. If not try another dealership if there is one close by to get a second opinion.

 

That's another red flag in my opinion. There are lots of things that can cause a misfire code. Your SA has just grabbed hold of a frequent problem and thrown it out there as the problem without really doing any kind of diagnostic work on your MINI.

If they can't be more accommodating and thorough it helping get your MINI back to full health, you might want to start looking for another dealership if there is one close by.

With your low mileage use, you should be changing your oil at least once a year.

 

No sarcasm meant. More like shock. You should definitely be changing your oil at least once a year.

BTW, as a new member of the forum, and don't forget you're asking for help, you need to calm down just a bit.

 

I emailed the service manager at the dealership, and asked for a diagnosis of misfire faults as soon as possible. The service manager replied "I’d first like to reassure you that as long as your MINI is driving normal you will not cause damage." He also set me up the first available appointment with a loaner late June. I have to wait for more than 20 days for the diagnosis now.

 

Update: The check engine light came on again this morning a couple of minutes after I started the car. I have only driven 50 miles since the dealer cleared the code without a full diagnosis.

I drove my car to the dealer. They will do a full diagnosis this time.

jcauseyfd must be right that there is something else that is wrong with my car.

 

I had a check engine light come on and my car felt like it was running on 3 cylinders. I took it to the dealer twice. The second time they did a carbon clean-up under warranty. I think it is a $600 job. After that the light came on again and they replaced the lower pump. What the heck at 28K miles. I didn't understand the failure and frequency and I'm a Senior Mechanical engineer. After month or so I traded the car in....

Good luck with your '09. I had the same year....

Jim Davis

 

Sorry to hear what happened to your previous mini.

My car has a mileage of only 8.5K.

Did you trade in for another mini?

I purchased my car in 2009/09. The four-year warranty is gonna expire this September.

 

I became gun-shy because my car warranty was going to end in 2 months and they wanted $2800 for an extended warranty. Really I have to pay $2800 so I can drive my car 3 more years or so. I traded it on an Elantra GT ( my girlfriend has one) and it has been really reliable & trustworthy. But not so fun to drive so I bought a '97 Miata as a fun car.

I wanted to keep the Cooper S but it was in the not as reliable as I thought it would be. It was mucho fun but the thought of the car stalling on one of hills where my girlfriend lives left me uncomfortable.

So there it is, my Cooper S looked great, loads of fun. But....

 

Results came out. Consistent with what you said, the dealer said it was due to carbon buildup.

And the dealer said it will not happen again. Based on your experience, I do not know how much trust I should give.

 

Carbon build up....hmmm. The code lights. I had my next neighbor check the code with his diagnostic code reader. I also had a spark plug pack go out to at the same time. I just could not believe an electronic part failure.

Stay on top of your maintenance and check that oil. I like cars alot, I just could not believe my Mini had certain issues.

 

Hopefully things work-out after the carbon clean out. And you were covered under warranty

 

I had a similar issue. Misfire code. Tried to remove the CEL by purchasing a scan tool innova 3040a, and it read the code fine and spit out the misfire codes; but when I went to remove/erase the code; it says it did it; but the CEL light remained.
Brought to dealer, they said it was carbon build up, charged me about 400 to clean the intake values, and explained to me its the ethanol is gas, so to use that techron fuel injection cleaner (techron suppose to fight against carbon build up) supposedly every 3rd gas fill up, which seems excessive to me, but I have a friend at work who does it ever 2-3 gas ups on his mini S.
Also researching ethanol-free gas.
I think I'm gonna start another thread becuase I am curious what scan tool I should buy to be able to reset the code? I was told by innova.com that the code did not reset becuase the issue needed to be resolved. But I'm feeling doubtful my scan tool that I paid 100 for would ever get rid of any CEL?

 

I have a 2007 mini S (59,000 km) with pending p0300, po301 & p0304 codes.
These were not stored codes but pending codes off one of the two modules.
These codes were generated when the engine was running and after I accelerated up to ~3000 rpm.
There were no codes stored.
I used an Autel AL619 to diagnose.
It cost me $170 online and it works great on all my cars including BMW 740, Mini R50 & R56 and Mazda 3.

Car was brought to the dealer since it takes a long time to start when its cold. no problem thereafter.
Dealer advised that they needed to do a carbon cleaning before they would diagnose further.
Quotation for decarb was $900.
They didn't even try to do basic diagnostic by checking the basics first like spark, gas, ignition coil, fuel injector, etc.
They stood firm it was carbon buildup and that was that.
This must be a very common problem for them to behave like that.
They are also getting rich on it.
So I told them to go fly a kite, paid the $134 diagnostic fee and brought the car home.
Unfortunately, another dealer is in another city.
So I will try to decarb it myself using Seafoam on the weekend.
However, I will check the spark plug, ignition coil and injector on cylinders 1 & 4 before I do.

 

I tried STP gas treatment because I was sure I got a bad batch of gas with the same codes you had and it worked after running the car about 30 miles. The check engine light went out by itself before I could get my ScanGauge II. I cleared the codes and so far so good.

 

I also have a 2009 Mini Cooper that has carbon issues. Today my car stuttered and stalled. I re started it an made my way to the mini dealership in Calgary. The intake was choked off with severe carbon deposits. I run my car pretty hard and in sport mode. The intake needs to be walnut shell blasted to get it cleaned. 68k on the car. My estimate.....$2750.00 the valves are carboned up as well. Cracked manifold, and gasket leak. I don't know if this is all connected but what a hit a week after Christmas. I was told a few reasons, shitty gas, driving slow, and the erratic temperature changes in southern Alberta. Apparently there is not this problem anywhere else. To boot September 20th it was in for a check up because the warranty was up at the end of September. Nothing was found. I only put 3500 hard km on the car between then and now. Not to happy

 

Carbon buildup is not a problem anywhere else in the world--search on the forum for it, and all 68,244 threads talking about it are only people from Alberta...

 

There's a good .PDF write up on carbon cleanout for R56 MCS. The article basically tells you to get a walnut blaster and blast the valves when closed. The parts were bought @ harbor freight. To do this with a BMW carbon cleaner cost the dealership close to 2k. If you do that @ home, you can spend close to $100 but get the job done and do it every 30-60k. I hope you guys don't end up shelling a out $$$ for this job. I ended up doing it myself - estimated time is around 6 hours (first time). Second time maybe 4 hours. Not including buying the parts and prepping the home made carb cleaner.

 

I had it done at a dealer recently, cost me $1200. Next time can I just bring it to you? XD

 

If you're near Philly...

http://store.helix13.com/helix-walnut-shell-blasting/

 

A few years ago I wrote one of the PDF s for using a Harbor Freight blaster with walnut shells to remove carbon build up ( https://www.northamericanmotoring.co...ss-3-27-13.pdf ). The cost for materials was less than $100.

I completed the first valve cleaing at 33,000 miles and the valves were spotless after blasting. After cleaning I added an oil catch can and blocked the lower PCV hose - both are supposed to reduce the chances of carbon build up.

I make a lot of short trips. I drive almost 100% in sport mode and I accelerate briskly. After all, that is why I drive a MINI! I use only Top Tier gasoline suppliers. I change oil every 7,500 miles. I think the short trips increase the chances of carbon buildup.

The car runs so much better with clean valves!! After less than 15,000 miles since the last cleaning my car threw a check engine light (CEL) and I got a low mass air flow (MAF) code. The valves were again heavily coated with carbon deposits! I had noted that the car was not as spritely and I noticed light bucking under light load acceleration.

I cleaned the valves again. It only took about 3 hours this time. Man,what a HUGE improvement. Much smoother engine, notably more power, and much more eager responsiveness. CEL is gone.

Two cylinder's valves were much more heavily coated than the valves of the other two cylinders and this means all 4 cylinders could not produce equal power. This increases vibration and adds stress to the engine. I believe operating an engine in this condition is harder on the engine.

MINI is certainly not the only direct injected engine that is experiencing carbon buildup on intake valves but I believe this procedure will be required routinely to keep this engine running well. I feel that the frequency of the required cleanings will vary with driving style and the trip profiles (very short trips, longer trips etc.).

With direct injection no gasoline vapor flows over the intake valves. With older, non-direct injected engines the gasoline passing over the valves kept carbon build ups from accumulating. Fuel detergents and additives increased this cleaning power and that is why car manufacturers came up with Top Tier fuel ratings to indicate brands with sufficient detergent to prevent intake valve deposits.

With direct injection this cleaning by the gasoline can NOT occur as the gasoline is injected directed into the engine - DOWNSTREAM of the intake valves.