I just got back from the dealer. I brought my 2012 CMS in since I noticed an obvious difference in the "boost" at around 2500RPM. Previously, I'd hit 2500rpm and the car would just go. Since a recent longer drive (450 miles roundtrip) I notice the car is just not punching when I hit that mark on the gauge.

So I brought it in to the dealer and they mentioned a few things. They said it could be some minimal carbon build up in the fuel valves. They also asked what fuel I was using. I told them the honest answer, what my MINI advisor told me to use, which was 89. I was immediately told I should have been using 93 and never lower than 91. Now I guess that is partially my fault since I just trusted my advisor and didn't read the fueling section in the manual. They recommended finishing off my current tank and then begin using 93. I asked about the sluggishness and if it will it persist. He said it might and that they couldn't go and clean the fuel valves under warranty unless they had a code for it when scanned.

When I spoke to my M.A. about this he said he didn't remember saying to use 89 but that I could use a fuel additive that could help with the possible carbon build up.


A few quesitons:

-Does this sound plausible?
-Since they won't clean the fuel vavles under warranty, what would be a good additive to use to get the job done?


Thanks

 

You didn't say how many miles?

The direct injection engines won't respond to fuel additives in the gas tank trying to clean the valves, since the fuel doesn't flow past the valves (by definition).

It seems early for carbon cleaning (again, are you at 50k miles or more, or ?), esp. with the PCV changes made for the N18's (that's correct for a CMS? I assume so, I have a 2012 MCS).

Just the engine computer dialing back after a life of 89 octane? I'm staying tuned, sorry I just have thoughts, not a real answer for you.

 

I would try a can of BG 44k. You can't get it at the big auto stores. It's sold at local shops, but also on eBay. It gets good reviews, from what I've been able to scour from the net. There are also some before and after photos on bgfueltest.com that shows some cleaning ability on a direct injected engine. I've started to incorporate it into my normal maintenance schedule. I'm going to do a can every oil change. A can is about 20 bucks, so it may be worth a try. It is certainly cheaper, but probably not as effective, as the $800 walnut shell blasting that MINI uses. If you try it, be sure to let us know if it helps or not. Stick with 93 octane!

 

A good friend of mine owns a Volvo & Saab automotive repair shop. He recommends the Chevron Techron (just google those two words) fuel injection cleaner. I get a box of 4 bottles from either Sams Club or Costco (sorry I cannot remember which one). I use it as a preventative and never had a problem. I do not know if it will cure your problem but it is a cheap solution if it works for you.

 

My MA said I could use 89 too, which is the mid grade here in Colorado. But I'm a firm believer in following the engine spec.

I've heard only good things about bg44k but never tried it myself. Some people swear by seafoam too, but I hear your exhaust will smoke from all the crap it cleans out.

 

First run the specified fuel for your vehicle. You caaan run 89 but the motor prefers at least 91. Techron or BG44k are decent. How many miles do you have? Carbon buildup is usually seen in higher mile cars that are driven gingerly.

 

How many miles have u driven? How bad is the no boost? Can you time the 0-62mph?

By the way I recall reading somewhere that you should drive a bit wild, hitting the redline more often to clear the carbon buildups? Is this true or a joke? Or I remembered incorrectly?

 

I drove a MINI that was exactly the same as mine, except that it had always been filled with regular grade gas. It had markedly less power than my MINI.

The Engine Control Unit, will retard the spark to avoid detonation, when lower octane gas is used. The engine power output will be reduced.

Before you spend any other money, just fill it with the high octane stuff and see if your engine's oomph comes back.

Dave

 

Thanks for all the info. I currently only have 4500 miles. I only just experienced the lack of boost. It was running nicely before that. I have about a quarter tank left and then I plan to use the 93 to see if there is a difference.

I read about the Chevron Techron and the good results from using it. Also read about the "Italian tuneup." Kind of hilarious and amazing.

I am really curious if the fuel is the issue here since it was running fine previously. From what you guys are saying, 4500 miles shouldn't be enough to create carbon buildup. That makes me wonder why the dealer would say that.

I am going test 0-62 tomorrow and see how long it takes.

Man is is frustrating. All was going so well. I just hope it's not a sign of things to come. I will keep you all posted on my findings.

Thanks

 

Was able to get and do the 0-62 test. Timed it at 8.9 and that was with a very slight roll up.

I am going try the 93 fuel this weekend. Also ordered a 12 oz bottle of the Techron which I will hold on to in the case I don't see a difference in the performance after the premium fuel.

 

A quick update...this weekend I finished off the last tank of regular fuel. I added the Techron and then a tank of 93. The car definitely seems to have regained power but I did notice that it's more even and smooth where as before there seemed to be more of a contrast in the pre and post 2500 rpm boost. This isn't a complaint since I find the ride to be more pleasurable now.

I will update this thread as I go through this tank and any noticeable changes occur.

Thanks again for all of the tips.

 

gob15 - I am glad to hear things are better for you. In my past experience of using the Techron, sometime the tank that I just put the Techron in does not seem to run quite as well. Note I said sometimes - who knows it might just be my imagination. I know the following fill up the car runs good.