Lately I have been having rough idling and hesitation while on fist gear and stuff, no check engine light or anything, i do have the ac turn on, but didnt have problem before. its something that has been gradually getting worse, my car has 30k miles and today it went for its second free oil change(i do change my oil every 5k miles) and they told me it may be carbon biulding, and of course they clean it up for $210 they shut the fuel lines and throw a cleaner in there to clean all that area( kind of like seafoam?)
Do any of you have this problem on N18 engines?

 

No they do this crushed walnut shell blast into the intake chambers. I would jump all over $210 because the last quote I got was over $600.

 

Lol, I remember seeing your car at mini today. crazy.

 

Lol yeah i had my last free service, whats wrong with the black cooper all jcw'ed up? That car was just bought

 

I'm trying to think of the car, you're talking about the one with the splitter and the carbon fiber wing right?

 

Yes, i saw it at another dealer just a week ago

 

Ah ok, Yeah I was looking at it today kinda odd grill. I'm not sure what it was in for, didn't ask and I got there after the owner dropped it off.

 

Sounds like the early symptoms of Needed Carbon Cleaning. How many miles on the MCS? If they will really do it for $210 i'd jump on that deal, as most shops charge 165-180 for 1 hour min. diag. and will usually offer a discount if you decide to perform the needed service from the initial diag. So...basicly for $40 you can get the complete service, thats a steal.

 

Don't know about where you live but here in socal carbon cleaning is covered under warranty.

 

There are two different services.

1. Fuel system cleaning
2. Walnut shell blast

I think he's getting a price quote for #1. #2 is usually +$600.

 

2nd country boy, The 210 is very much likely the fuel system cleaning, which doesn't do anything if its poured into the fuel... since that will never reach the intake valves!

 

Curious if the OP has experience any appreciable oil consumption, or noticed that the oil level was low at any point in time.

There is an expanding group of thought that both oil consumption and intake carbon build-up might be correlated to malfunctioning of the internal PCV valve located inside of the valve cover. No real evidence yet, only a smoldering gun...

 

You realize all cars have carbon/oil most blow by, right? The function of the Pcv valve is to release crankcase pressure, and also has a egr function to reduce emissions when cold (when there is the most blow by). The difference is port injection (vs direct injection) has fuel that washes the back of the intake valves preventing build up of the carbon (like you see in the Shell commercials. We lack fuel in this area as our injectors are located downstream of the intake valves.

Some new cars with direct injection use an additional smaller injector in the port to wash the valves.

 

I really havent check the oil comsumption, kinda gave up trying to read the disptick

 

Big issue on DI engines for sure. My 2.0T TSI will need a carbon cleaning done here soon also.

There has been a lot of discussion on what causes this be it the PCV system or what. I can say the a catch can does not make any difference at all on the FSI and TSI 2.0T. Some have installed PCV block off kits and say it helps but no proof on that at all.

 

Unless you've started changing your oil every 3000 miles, that's a good way to blow your motor. Or maybe just your turbo.

If you're going by MINI's absurdly-long oil change intervals, you really really really need to be checking the oil level regularly!

 

I change my oil every 5k

 

Is it possible that something else is causing the rough idle? It seems that carbon buildup is a little early in your car.

 

All correct; however, there are other threads here on NAM that report instances of the internal PCV value getting gunked up to the point that it can't close completely when the intake manifold transitions from a vacuum condition to being under pressure from turbo boost. If that is indeed happening, the PCV would permit the normal boost condition to actually pressurize the crankcase, exacerbating the blow-by and probably doing other bad things too.

 

I had my valves cleaned via walnut shell blasting at about 39-40k miles, another friend around 34k. 30k is not far off.

 

Any chance you have an After photo?

 

Nice! Long Tran BMW! LTBMW is a good shop. Didn't know they did the walnut blasting there. That picture is what we would consider a level 5-6 of carbon deposit. You'd laugh...but I've actually seen even worse, way worse.

 

Sure do!



Yup! Long is a long time friend. I was the first DI vehicle to get the service done. I was his inaugural start of this service and I'm just here to help fellow members.

 

BTW! If you know Long, I hope you know he has a meet on the 15th, Imma try and drag along a few other members on NAM to go. I'll try my best to get my car ready for this meet.

Wheels, a bit of repainting, meth kit install, detail. Hope you can make it, I'd love to meet more R5x peeps. Tim (my1stR56) just did the walnut shell blasting done today there.

sorry OP for a bit of the off topic banter.