My MCS has been feeling slow for some time now. Throttle response is horrible.The car feels best around 3.4-4.5k rpm everywhere else is not very exciting. Everyone is telling me I’m just getting use to the car I believed this for a while until I started realizing my driving style has changed to accommodate the sluggish acceleration. I have to downshift to forth sometimes to third too quickly passsomeone on the highway and even then it’s a struggle. In the past I could easily hear the tires break off the line going into first, second and sometimes going into third (using same summer tires just newer version). Now my MCS feels like an MC.

I have a stock 2010 Mini Cooper S Mayfair edition witch I boughtbrand new. I’m currently at 90k miles and worried as my warranty/maintenanceplan is about to expire. I have been to the dealership 25+ times since I boughtthe car but that is including regular maintains not including tire rotations.

I love my car but this slow acceleration makes the car frustrating to drive and the idea of having to come out of pocket for any repairs is scary.Any ideas. I am will to do some bolt onand maybe a cobb AP if I can find one but would like my car to be healthybefore I go down that road. This is my daily driver.

 

It could be a myriad of things sapping power from your engine. True, our minis aren't the fastest, but you haven't felt sluggish acceleration till you have driven a civic or an older v6 mustang. There is a decent sized aftermarket for the r56, and a solid 2k can get you some good power bumps. I will agree that when I get to 90k, I will be just as wary for the inevatable huge repair bill that will be coming.

 

Ever have the valves cleaned?
The n14 powered minis have TONS of carbon issues.....

 

have the high pressure fuel pump checked. the warranty on these has been extended to approx. 100,000 miles. i am on my fourth pump, with varying symptoms similar to what you are decribing

 

Sounds like you should purchase my Sprintbooster

J/K

But seriously, when I took the SB off my MCS N18, I felt like there was some lag, or lack of power. It took some time to adjust to the way it progressively builds boost. The Sprintbooster made it feel like night and day, but once I installed my Methanol kit, the SB was causing me to always be in that 8-9psi threashhold, activating my W/M pump. I was blowing through a 3 quart tank in no time, LOL... But the SB does make the MINI more fun to drive in some aspects.

Also, when was the last time you checked your Diverter Valve. I would start there. A weak worn out spring, or worn out diaphram could cause you to not hold boost as it did brand new. I recommend checking it, Purchase a new stock DV, I believe the N18's came with a newer version than the N14's. My bad if im wrong on that, but it is a known weak link in the turbo set up. Upgrade the spring to an Alta Uprated spring for $20ish, and you will deffinately feel some crisp shifting and higher boost capabilities, pending your stock DV was needing to be replaced, of course.

Good luck, and PM me if want a good deal on an SB vII.

 

As I recall, the 2010 has the n14 engine? At 90k miles, you are way past due to having the valves walnut blasted. What you are describing fits dirty valves..

 

I have to agree that Carbon Buildup is likely the cause. I would have someone check your intake and valves for carbon and a walnut blasting is likely in order.

I also would get a boost gauge. I recently had a leaking hose connection between the intercooler and intake. The vacuum/boost gauge on my Torque app told me that I was only able to generate about 4 lbs boost instead of the normal 12 -13 lbs.

Runs great after fixing the leak!

 

I had a very similar issue and you're going to get a lot of people tell you all about walnut shell blasting and this and that and all other things.

I take care of all my cars like no ones business, perhaps this is my aviation training to replace before breaking and doing a myriad of overhauls on engines, but I did let my mini slip by 60,000 miles before doing any real "maintenance" and I got bit by the bug you're talking about.

Now, considering they have either Platinum or Iridium plugs from the factory, typically they're supposed to last between 75,000-100,000 miles, but I call BS, especially since I've worn them out in my race bikes in less than 5,000 and my 328i in less than 50,000. So, me just being lazy, I had all the problems you're talking about and EVERYONE pointed to carbon buildup, which I can understand given GDI in these vehicles; however, I also ONLY run non-ethanol gas, which I know doesn't eliminate carbon buildup, but greatly reduces it.

What did I do to fix my problem? Simple, cleaned and oiled my K&N (I don't care what any of you say about those filters, I have never had an issue with them before) and then I changed my spark plugs, which looked like absolute crap! Now, you'll get people tell you to replace with Beru plugs, but not being the biggest fan of Federal Mogul and knowing NGK puts quality of manufacturing above all else, I went for the NGK ILZKBR7A8G, which are one degree colder and more suited for when you're ready to apply more boost. Just FYI, get the magnetic 15mm socket to work on them, you'll love yourself for that!

Now, I also had the issue with sluggish cold starts before the plug change out and just a wee bit afterwards. My next step was Toluene, especially since I can get my hands on it for cheap! I won't go into Toluene but there are plenty of write ups on it and lots of people have used it with success to clean their fuel systems out and remove carbon, with the added benefit of higher octane. So, I did a 22% mixture of Toluene to 93 Octane non-ethanol gasoline the next day. At first, the Mini didn't seem happy, drove it for 10 miles in stop-n-go, it just didn't seem happy at first until I hit I-540 and opened up the throttle, from first gear to 5th, tapping the redline before shifting, and settling down to 75mph for a nice long drive around North Carolina to waste a tank of gas. In the end, my car idles smoother, starts like a bat out of hell, and accelerates like new again.

So, do yourself a favor: Use the NGK ILZKBR7A8G (for the turbo motor), new air filter, and get yourself some Toluene, 1 gallon will do ya, and see if you can find some non-ethanol fuel to mix with it and get to driving, some in town, then beat on it like you stole it, and hit the highway for a while to see how it works for you. If you're still getting the carbon buildup symptoms, you're likely too far gone down the path and need that walnut shell blasting.

Just in case: Other than my K&N, the car is bone stock for the time being. My parts are all sitting in boxes here in my office until I get a chance to drive to Miami to get my car tuned and tested by, whom I consider, a master in what he does.

 

Get a tune when all is said and done. Once the valves have been cleaned, get a Battle Tune and they can adjust the throttle response as well to your liking. You wouldn't need a Sprint Booster and you'll gain more power. Like your Mayfair, I have a '10 Camden with 72k miles and regularly, and religiously change things out waaay before it's necessary. I've done so much to her that there's no way my MINI is leaving the stables.

Good luck to you! And if you need spark plugs, I have them fs in the marketplace. Pretty much new plugs.

 

I had my intake valves walnut blasted at 47K and boy what a difference, before the walnut blast I didn't hear the turbo whoosh because my engine was being choked by filthy carbon deposits in my intake runners and valves! You might also try a few bottles of BG 44K to clean the fuel system and combustion chambers, they'll look just like those filthy valves did before cleaning.