I've noticed that when I am on the freeway (60+ MPH) and I really get on it and accelerate quickly for whatever reason, my engine stutters/hiccups. I don't really know how else to describe it other than that. It only happens at higher speeds and when I'm accelerating quickly. Any ideas of what could be causing it? It's really odd. I always put premium gas in, and the only mods I have that might affect something like this are the NGK Iridium plugs and the ALTA 17% reduction pulley.


The closest MINI dealer is 2 hours away, so I thought I would post the problem here before taking it in. Plus, I don't know if my ALTA pulley voids my warranty.

 

I would put $ on the plugs or wires. Sounds like you arent sparking correctly. It could also be a air/fuel ratio problem. I would put your stock plugs back in and if that doesn't help (I think it will) have the ECU flashed.
I dont think your pulley will void the warranty for this issue

 

Could be bad gas, too. I went to a different gas station for a couple fill-ups, and the engine would stutter when I blipped the throttle. I thought the engine dampener was shot, but everything was fine. I went to a busier gas station, put in a fresh tank of gas, and all the problems went away. The difference was so dramatic. Try adding some octane booster and see if that makes a difference, too.

 

Fuel filter, bad o2 sensor, ecu problems, dirty air filter.

a couple potentials

 

If it was the plugs, why would it only happen in 6th gear at higher speeds? My previous car had problems with the plugs/wires, but it cut out at lower speeds as well.

Also, I thought it was better to have the colder iridium plugs with the reduced pulley?

 

Hmmm... don't know about the gas part. I put good quality gas in it, but I suppose giving octane booster a try is worth a shot.

 

Engine knock will usually occur when pulling hard in higher gears (but not limited to). It actually sounds more like a chattering noise. I have had good results from the Techron fuel additive by Chevron. I try to run some through the tank once every 3 mo. or so.

 

try some BG44K every 8-10k to keep that pup running fine.

 

It's not engine knock or chattering, it's a "hiccup" in power. There is no noise associated with it, just a couple split second hesitations while under full throttle on the freeway.

 

Three things yer motor needs: fuel, air, spark. Air's probably good. You say you use good fuel. Narrows it down somewhat. Under certain load/speed combinations, plugs or coil could be misfiring. You might try pulling codes to see if there is a intermittant miss showing up -not enough to trigger the SES light, but enough to register. Plug wire could be going, too. I always recommend starting with the simplest thing first, saves time and money.

-skip-

 

Spark issues would manifest themselves at all RPM's, not just high gears cruising on the highway. Usually when there's an issue with spark it occurs at higher RPM's anyway. I've never seen a misfire not throw a flashing SES and automatic limp mode. I've also never seen plug wires go out, not sure why people change them. My coilpack was having issues so I bought another one from the dealer. I've worked with people that built 300+ wHP monsters on stock coils and plugs. Sometimes I think people just like spending money on stuff just because there are parts out there to buy .

Hesitation could be any number of things, clogged air filter, a bad batch of gas (Happens even at top tier stations ), issues with your clutch, the list could go on and on. You need to take it to a mechanic and have him drive it and look at it.

How many miles are on the car? Despite the fact that MINI says the fuel filter doesn't need to be replaced, they get RIDICULOUSLY dirty. Mine was black when I changed it at 15k miles. You should really change it every 20-25k miles max.

 

Thanks to everyone for all the awesome input and suggestions.

My car has 30k miles on it. I purchased it pre-owned with 20k on it. Maybe I will have my boyfriend change the fuel filter this weekend and put some of the injector cleaner in that Sequence mentioned above. If that doesn't take care of it, I'll take it up to Scottsdale MINI to have them look at it.

 

Yea, i'd run the gas out of it then go put some Chevron in it. Run a tank of "Seafoam" too, it's a heavy duty injector cleaner. Changing the fuel filter can't hurt, and it's pretty cheap, only about $30 in parts, and takes about 30 minutes to do .

 

I'm having the same issue with my car, a 04 MCS with 75 K miles. The car runs really well until I drive for about 20 minutes. After that I have a severe misfire under heavy acceleration. Idol is smooth and I have NO warning lights. The plugs, wires and injectors are new (less than 10 K miles).

 

My R56 S (2007 feb build) has started stuttering usually when Im cruising at a constant speed then mash the gas. It stutters 3 -4 times then surges forward like its supposed to. Originally I though it was gas because it made this weird diesling noise, like when you go up hill full throttle in and old car w/ bad gas.
The car has since been running on the best gas I can by which is 93, Any ideas? car has 30,000 miles on it, and is stock again.
like I said, its only when cruising at constant speed then hit overboost
I search for threads if this is a repost, please reply w/ link?
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This is a first gen thread......try posting in the second gen thread.

 

Its the spark plugs....had my 15% pulley done today and its does the exact same thing.....and i also put in the colder plugs. I was told to check to make sure they are tight, but if it still does it im switching back to OEM plugs

 

Did anyone ever get this problem resolved? The few threads that I have read have had a bunch of good advice, but no clear problem and solution. My worry is that the few people with this problem (me included) have pulleys. My hope is it's something simple like the spark plugs (going back to the stock plugs) and not an inherent problem with the smaller pulley.

Thanks.

 

I changed back to my 3 year old stock spark plugs and the problem went away. I was just about to hand the keys (and a lot of money) over to the MINI dealership to see if they could fix it, and I thought I would swap out the spark plugs just in case. I couldn't believe it worked.

Now the next question: Are the one temperature colder plugs necessary with a 15% pulley? If they are, I'm not going to get the NGK ones again.

 

actually ... no . i had a coil go bad and it would only show up with the hesitation and such when i really got on it with a load . if i drove normally it never acted up . so i'd go with the mariner on this one and focus on spark . cracked plug insulator or coil 'd be my guess .

 

I also had a severe studder and I first thought it was GAS, I recently put new Brisk Silver Plugs, new hd wires and coil from MSD car ran good the one day sputter DSC light code 036. I checked everything and put the OLD coil back on and it runs smooth as silk. New coils can fail too, so check yours as well, assuming new means working, isn't always so.

 

MINI_Britta, what was the final root cause for your MINI? I have an '05 MCS and this happens pretty much as you had described, cruising speed on the highway and then full throttle. It doesn't happen every time, but enough that I can reproduce it pretty regularly. Sometimes it is a single stutter/hiccup, sometimes it is 2 or 3, then everything goes back to normal.

I also have the 15% reduction pulley and the NGK colder plugs.

Hoping you can let me/us know what happened with yours. Thanks!

 

bypass valve it happen to me

 

I have this problem in my r53 JCW (200hp) 2004 model to
With 3rd and 4th gear and maximum acceleration, full throttle have power loss between 3000 and 4000 rpm when accelerating from 2000rpm like 2 or 3 small cut offs (stuttering)
The problem start after the inspection 2 service at 82000 km
they put wrong poly belt and wrong plugs BKR6EQUP fitted rather than the specified BKR7EQUP and start stuttering
I go the next day and they put the correct plugs and belt but the problem don't go.
The dealer check the fuel injectors and they are OK
They change the fuell filter they chek the elektrical its ok and reprogramming the ecu but nothing
It only happens when accelerating past s out 3000/3500 rpm and feels like the power cuts for s moment.

if anyone can help me I would appreciate

 

2005 R53, 53.000 miles, only mod is 15% pulley done last march.
a month ago engine started hesitanting (hiccups) under acceleration, in any gear, mainly between the 2500 and 3500 rpm range. very anoying and for what I´ve found searching this forum there is no clear solution.
Other thing I´ve noticed a couple of times when stopped at the red light is that I the car makes some kind of superfast shorcircuit, lights on the dash blink, radio turns off, ABS light flashes one time, fuel gauge goes back and forth. Last weekend I checked battery, spark plugs and cables....and seem to be fine.
As this happens on a particular range of rpm's, I don´t think it is a bad fuel filter. On the other hand if it was something like misfiring, should it be happening all the time?
all comments and suggestions are welcome....