So, I picked up my Mini a few months ago with approximately 47,500 miles. Since I used to own a 335i with the N54 motor, I was very aware of carbon buildup with direct injected engines. Instead of paying for the service I decided to buy the tools and have a go at it myself. Good thing I did, I saved some dough and was able to perform the service on my Mini as well. It is pretty straight forward without too much fan fare.

After cracking open the intake I was actually surprised at the lack of carbon buildup and oil residue. With 51K miles it was actually not too bad; I expected worse. Oil residue was pretty much non-existent in the intake manifold and there was very minimal carbon on the throttle body. Good news! Since I had come this far I decided to go ahead and clean them up. The only real pain in the butt was when blasting my shop vac could not pull all the shells from the very bottom on the intake track for some reason. I didn't have this issue when I did this on the bimmer's N54. So after each blast, I would have to put another attachment on the vac to get all the way in the intake track in order to clean it up. I figure every 50K for this engine in my environment is a good interval.

End result was almost 1 mpg better fuel economy and better throttle response. Check out the pics. I was going to put them in order with comments, but either they changed something or I forgot how to do that!

 

Nice find on the JCW.

They say that the N18 should be better that the N14. Looks like it is.

So, please post a little more about how you did the cleaning. I see the advertisement for the Ryobi drill (), but can't quite tell what the brush is. Nylon? I take it that you used those to scrub out the carbon? And how do you work it around to get to the far side of the valve where it appears to get tight?

Thanks for posting the pictures. I may be doing mine in the near future.

 

Eddie,

Check out the attachments, they should give you all the info you'll need. If you decide to buy the cheaper mini intake adapter (3D printed version) vs the more expensive (metal) version. Don't be too hard on it or it might crack like mine did. I just taped it up and kept going with mine.

Also, I used the drill and attachment (nylon I believe) to remove the stubborn carbon deposits that was on the "neck" of the valves. I just worked it by feel by placing the extension in first then attaching the drill once I had it where I wanted. It seemed to work well but it did scratch up my valves a little. So maybe you can find a brush without the metal core/center if you want to prevent that from happening to yours. Also pay attention to the intake manifold removal. There is a 10mm bolt underneath the manifold that you can get to from the passenger side wheel well after you remove the tire. Your manifold WILL NOT budge until that bottom screw is out! Good luck!

As far as the procedure

 

 

Hmmm, I'm not sure on that one. Maybe someone else can answer that question. From the looks of some of the N14 engines I'd say you probably could get away without any type of cleaning for 100K if you don't have a super short commute. I tend to drive about 20K a year and most of my trips are on the longer side. Also, weather and driving style (lead foot vs. babying) could contribute. I'd love to see some other N18 intake tract pics at around the 50K mark with accompanying info on driving style, oil change interval and regional demographics.

 

Hey, Fantastic Writeups!

Thanks...

 

 

Nice. Do I see a car that is headed to the track?

It will be great to see a write up on these. Just a thought, there are already some really good DIY write ups here on NAM for installing these. You may want to see if those are worth augmenting versus preparing your own.

A pointer for you on removing and installing the front shocks. Once you have the pinch bolt loose on the steering knuckle, the knuckle won't come all the way off the shock without some help. My solution (found on someone's post a while back) is to tape (Gorilla tape works well for this) a 2x2 to the barrel of the shock, positioned under the spring perch and long enough to extend below the control arm. Use a floor jack to push the shock up (about an inch) so you can clear the steering knuckle from the shock. Do that again with the new shock and then slide on the steering knuckle.

 

 

 

Hey, looks like you may have some company at COTA:

https://www.northamericanmotoring.co...5&goto=newpost

 

Yes the B14 are on back order but the ST and KW's are on sale right now. I dont see any B12's? Unless I am missing something.

https://www.ecstuning.com/Mini-2007-...on/Coilovers/2

 

Great post !

Some thoughts... Once you've done the walnut shell blasting or other mechanical cleaning.... Follow up with the CRC or other more professional strength cleaners like the BG-GDI cleaners. Since the valves are closed for the service... it would be a good idea, IMO, to do a thorough intake/intake-valve cleaning chemical treatment... this will do a finish clean of the valve and the seat/valve interface on both parts.... as well as decarbonizing the piston face.

I'm a new, to me, R56 owner... I'll be doing intake system cleaning with the BG 260 GDI intake cleaner before every 4000 mile oil change. I've had good luck with the BG products.

My new N18 R56 has just had the Walnut blast done it's nice and clean and was not really bad before... so, keeping it clean as possible with out another walnut blast is important to me... PLUS... this will help to clean the domes and seats of the valves that walnut blasting cant get to.
Talked to my local BMW/Audi guy who knows me well... and he's said that follow ups with the BG-260 have solved some issues that the walnut cleaning could not fully remedy... like lost compression from a small bit of carbon on the valve face that couldn't be removed with the walnut shells as the valves are closed for this service. HMM.

I'll also be doing this myself... I'll know that I can do a thorough job without paying someone that feels they're on the clock and cant take the time I can.

On top of that... I'll be using a top notch oil that has low NOACK (volatility) numbers to minimize on the cause of the deposits in the first place ... The best I've found, in terms of a Super high quality, full synth, oil with low Noack #'s [6.0%] the Ravinol DXG that exceeds factory MINI requirements for API-SM... considerably lower volatility than the LiquiMoly, Amsoil or Mobil-1 I like in other non-DI stuff. The factory BMW/Mini LL-01 are horrible in this concern, no wonder the valves coke up!

I've always remembered the old ad from when I was a kid... "You can pay me know or pay me later"...
The N18 Seems to be a decent engine... and the deposits are no where near the problem that the N14's had... but I want to keep it that way for a while.

Seems to be plenty of atomizer kits for the BG liquids...at reasonable prices. I've had great results with the BG pro-grade chemicals... I believe they would function better to clean and keep clean our DI N14/N18 engines than the off the shelf 'spray cans'

Peace of mind for me.... and less hard work. Pricey oil changes... yep...I just hate downtime if I can avoid it, and take pride in my cars.

My 2¢















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