Okay, I tried to search deep into this forum. Came close to some answers but haven't seen a problem like mine yet.

Car is 2011 MINI COOPER S N18 engine

I replaced the spark plugs, did nothing.

I have a AEM Intake on the car. It has been super cold this past month (michigan), may have possible impact. AEM intake has been on since august.

Okay, I drive the car smooth and "normal" its fine. When I hard accelerate in a gear higher then 3rd it sputters and loses power (usually happens on free way to get to high speed, or passing another car). If I hold it down it kicks on LIMP mode, And engine light flashes. I turn off car, engine light stays on, and runs fine until I hard accelerate.

I have not heard of anyone else limp mode going on. I read about a TMAP sensor but that was in a 10 year old thread.

I want to fix the car from cheapest, thats why I started with the spark plugs.

Could it be the intake is doing something to a sensor? causing sputters? I am all ears and real answers will help. I will take it to a computer soon, but really want to know if anyone has an issue like this.

 

Looks like you will need a diagnostic done, no codes are showing up on the dash computer after the limp mode? I am thinking a big vacuum leak somewhere,...

 

I always think gas first, that would be the cheapest fix before going full on diagnostic stuff. I've had similar issues, just not in Mini as of yet.

 

then why no other reported symptoms like sputtering or high idle? a vacuum leak, even a small one, will trigger a code pretty quickly.

you need to get a diagnostic done with a code reader that speaks BMW, then go from there. the problem you are having sounds like a misfire under heavy load, which could have numerous causes like a bad coil, carbon buildup on the valves, failing HPFP...the list is really exhausting. you need to narrow it down and start eliminating variables. put the stock intake back on and see if it still does it to, thats simple and free (assuming you didn't throw the old one away).

limp mode happens to people all the time. its the car's way of telling you there is a major problem (which it may or may not identify for you) and preventing you from doing too much damage (i.e. driving 20 miles with a super knock condition).

 

at what RPM are you shifting when you 'stomp it'?

these lil guys like higher RPM ....

I always kept mine over 3000

if shifting low it could just be lugging . . .

 

Thanks for all the replies. I have Coils coming in as we speak. I will get the stock intake out of the storage. I did do sea foam, but did not put it in the gas yet. (waiting to get close to empty). RPMs is around 4,5000. but if I coast it, it sputters a little bit around 5000 or not at all. If I go hard (pass a car, get to 70 on free way, or fun) it sputters hard and limp mode goes on.

Thanks for letting me know limp mode goes on for others. I will just keep doing one thing at a time! just looking for similar instances that were easy fixes.

Car has 60,000 miles on it.

 

why replace the coils without verifying they are bad first? its simple enough to do, if you are getting a code on a specific cylinder, swap the coil out with one thats good and see if the code re-registers on the swapped cylinder. if the coil is bad, i highly suspect you would get a code since its easy enough for the computer to read through the CANBUS that something isn't firing right on a specific cylinder. ie P0303 = misfire cylinder #3, P0302 = misfire cylinder 2...

you need to a diagnostic before you start throwing parts at it. do you have a scan gauge or code reader/code read app? its amazing how much an OBD2 car can tell you.

 

Thats the plan. But its at 60,000 miles. Might as well replace them now anyways. Then when I get my hands on a computer, I will test the coils. So in the end not bad to replace cheaper parts at this mileage anyways. Work been busy, and most places closed when I get out. The weekend will have answers when I can finally go to a place like auto zone to get the codes.

 

My bet is on HPFP. Mine was replaced under warranty. How well does it start when cold? My first indication of failure was at about 50 degrees F. Started, stumbled, caught itself, ran the RPM's up. Then started losing power at speed sometimes. Actually cut out at times...backfired thru the intake/exhaust. Got the 1/2 engine symbol. Dealer replaced the HPFP under warranty. Good since then.

 

find an independent euro specific shop, the generic code readers can't always clear or pull all the info.

 

in michigan its been below zero these past couple weeks. and it has been starting pretty good. nothing scary until i hard accelerate. Could this be the pump still? I guess it could be anything.

 

HPFP, Coils..... as ideas to start with... but if its really misfiring / breaking up it should have some pending codes waiting to pop...

 

Okay, I had a guy scan it, and it came up with 2 misfires in two cylinders. I believe that is because I switched and moved the coils around. Therefore firing off two cylinders. Unfortunately I was in a rush and could not move them around again. I hope it is the coils.

 

I am sticking by HPFP being the issue. Sounds very similar to when mine went out. Known issue. Hopefully will be covered under warranty, or good-will.

 

If i is then thats bad luck. I think since I switched the coils around the code came up onto another cylinder. Unless a bad HPFP pump can misfire multiple cylinders which could be a conclusion. Coils will be in tomorrow. We will know by the evening.

 

Also this is a 2011 MINI, not saying its def not the pump, but the problem with the pumps was in the N14 engine. I have a N18 engine. The pumps were "updated" (i hope). It still could be the issue. But that is why I am doing the cheapest things first.

 

COILS CAME IN TODAY, AND THE CAR RUNS GREAT!!!
Always start cheapest. Sea foam: $10, plugs: $50, Coils: $120-250. Dealer would of charged me a walnut clean, plugs and coils, total from dealer: 500+

 

Good to hear! I hope that was all you needed. Be sure to give us a follow up in a week or 2 just so we know for sure.

 

Nice!

 

Glad you got it fixed! As far as HPFP goes, I think they are an issue in the N18 just like the N14. Maybe not as widespread, but still an issue.

 

Well……….. bad news. Did not drive it for a day now today sputter. I couldn't believe it. So I did some hard acceleration and bam, CEL and misfires.

Car literally runs perfect outside of just hard acceleration. It has been super cold here in michigan for months. 3 straight weeks of negative temps. It is hard to believe it is the HPFP since it runs fine at idle. It almost seems its a sensor of some sort. Could a sensor or gauge be off since it has been so cold??

Today it is high 20s warmest its been so far since I had the problems. This is frustrating. I don't want to buy a HPFP. I will end up doing it myself, but i want to know for sure.

 

First things first, get it scanned by a shop with a scan tool that reads proprietary MINI codes.

 

P0301 was the code.

 

The pump is still an issue.It wasn't updated for 2011 as far as I know. You will get multiple and/or random misfires when it is going bad. Also possibly fuel pressure related codes.

 

I would never put it out that it is not the pump. It just runs so well besides pops and sputters when I hard accelerate in only high gears. I plan on getting a HPFP now. I may just give in and pass it onto a shop/expert in case it is anything else.