Carbon build-up takes place on the intake valves, looking through the spark plug hole is the wrong hole to be looking down. I'm surprised he doesn't have a clue what you are talking about, N14 carbon build-up issues since it's release! Have a look here.

 

thanks for your input

 

The carbon build up issue is an obvious problem. While I am not sure how to eliminate this issue other than use Top Tier gasoline and perform a chemical induction service by inducing cleaner through the intake periodically.

My mini has burned a 2nd exhaust valve within 10k. Both times just after a heavy acceleration. The first time I removed the head, I had the valve replaced and head machined but did not completely clean the piston surface. Now that this has occurred a second time on a different cylinder, I have concluded that the carbon build up on the intake side if present will chip off and during its way out lodges in the valve seat of the exhaust valve causing it to stick open slightly. After consecutive combustion burns the valve like a torch.

Walnut blasting and top engine cleans are paramount after 50k. dont forget to drive hard every chance you get

2009 Mini Cooper Clubman S. 120k A.S.E Master Technician

 

Does your car burn a lot of oil?

 

Short starts and stops / not driving for long periods I found increases the build up more. We had a bunch of people with short trips complaining of quicker carbon build ups.

 

yeah, my 2009 Mini HardTop Coupe-S is just over 40K miles. I'm very concerned how much carbon build-up it may have.

my 2009 Mini HardTop Coupe-S (with just over 40K miles) has, all along, frequently had to be topped-off with oil, just about everytime I had oil checked.

at this point in time (with just over 40K miles) my Mini sit's much more than ever in-between mostly short trips. Although I do take it on vacation trips maybe once a year. I have noticed, it seems like, that throttle response may be slightly sluggish, or slightly delayed, compared to a few years back.

Looks like I'll have to inquire about walnut blasting next time I'm doing service

 

Yep. Or DIY: MINI style.

https://www.northamericanmotoring.co...-cleaning.html

 

wish I could, I'm in a wheelchair. Impossible for me to physically access, or even lift parts/components. So I'm forced to place trust in mechanics hands........

 

It used to burn oil prior to replacing the valve seals. White smoke after idle. We purchased it used and suspect previous owner used less than adequate gasoline and never cleaned the system, The direct injection seems to be the issue. Although walnut blasting does not clean tops of the pistons.

 

Just about every 50,000 miles the intake valves need to be cleaned to maintain optimum engine performance. Once the build-up reaches the maximum tolerable level, the engine will begin to run rough and misfire. You may have a rough idle, poor acceleration, stalling or single to multiple cylinder misfires.

 

Yes, the direct injection is as the direct injection sprays fuel directly into the cylinder and is mounted in the rear of the cylinder head. With the design of this injector efficiency and injection control greatly increases. However, the down side is the lack of fuel spraying on the back of the intake valve. This removes the cleaning effect port fuel injection engines get, a real benefit new engine designs need.

All of this and more is in our carbon clean up DIY, which is the method used before walnut blasting was introduced. It's on our site here: http://www.pelicanparts.com/techarti...n_Cleaning.htm

 

yeah, I'll be focusing on having my engine intake valves checked in the near future. Are those images you post from a "video scope"? Engine was not disassembled to capture this? Do most all Mini dealers use this technology?

 

That image is from inspecting the valves on our in house R56 with the intake manifold removed. You can see how we cleaned the valves, including this image, http://www.pelicanparts.com/techarti...n_Cleaning.htm. Figure 3 shows you what the chunks of residue looks like when they're scraped out.

 

oh, sorry to hear that, i did not know. My brother was in a wheelchair for a long time after his illness. The MINI was easy to get him in and out of in the front seat. Wheel chair went in the back over the rear seats folded up. Used to take him to the hospital allot in the MINI.

Whats you can do then is get a good mechanic ( indy shop ) and they should be able to do this for you , if they have done the BMW carbon blasting they can do the MINI one.

Let me know if you need anything else.

 

Mileage: ~51K
In shop right now for flush, clean, and reset of computer system due to carbon buildup. $130-ish for clean, $140-ish for system reset.
Also an (I've been told minor) oil leak but that should be unrelated.


There seem to be a lot of posts in this thread, but a huge range of years and models.


Never had this problem on my 2006 Cooper hardtop. But I don't think I'd cleared 50K miles by the time I traded it in.

 

That's because the 2006 Cooper is NA and not direct injection. The carbon issues relate mostly to 2nd generation N14 and even some N18 engine owners.

More info here: http://www.pelicanparts.com/techarti...n_Cleaning.htm

 

Thanks for the link! New (to me) things to keep in mind when I'm in the market for the next car.

 

2010 MCS. Did a DIY cleaning of the valves, at almost 55k miles, after misfiring/rough idle (no codes). I walnut-shell blasted and scrubbed them to bare metal. These pics show my valves less than 3000 miles after that. I've since installed two catch cans and will check the valves again this spring. Not sure why some of the valves look 'wet'; is this "normal"?








Another benefit of installing the catch cans: after replacing the pcv hose and plastic vent hose with rubber hoses + clamps, there is no longer the fresh oil/gas smell at the tail end of my 20-mile freeway commute when encountering stop/go traffic in the city. It seems that over time, the oem hoses don't keep their seal and allow fumes to get past their connections. Lived with that issue for 3 years and it's finally gone!

 

Much better. Looks like its the heat or the baking of the carbon on the valve, must be hotter in places.

 

w

 

78000 car miles. 20000 miles new engine. I'm 3rd owner. Change oil every 3000 miles. No oil leakage or real consumption. 400 to clean because other work is being done, otherwise quoted 1200 if I do it later.

 

S

 

I recently priced a repair between the two in south bay LA and the dealer was 200 higher. Not wildly different, but enough to count. I tend to do larger repairs where there could be warranty implications or class action results through a dealer so you're covered...

 

2010 MCS Convertible 42K miles

I was getting a rough idle and jerky acceleration before the engine cut out on me at a stoplight. The engine light came on afterward. I only use premium gas and regularly drive it over an hour on the highway each way about 2 days a week. 80ish mph. Other than that, not much highway driving.

The dealership says it's carbon buildup and is charging $754 for a walnut blast.

 

My car is at the dealer for a timing chain and they reported that it had carbon build up. I mentioned that I haven't lost any performance and it definitely is not sluggish. He recommended the carbon cleaning based on a code. I'm going to wait until it affects the performance due to the high cost of the cleaning...roughly $900. It is not covered by the maintenance nor the extended warranty.