Suspected misfire on WOT!

[Benny No.1]

Hi,

I'm having a strange problem... My R56 Cooper S is misfiring on WOT, now its not happening all the time and I'm still in the process of figuring out what conditions cause it. But so far I've had it happen to me in 4th and 5th with WOT and when I'm about to hit peak power. I've changed the spark plugs and it seemed to cure the problem but it has started to raise its head again after about 5k miles. Is there anything else i can check? or any ideas on what might be causing it?

Any help will be appreciated!

Ben

[Boro Boy]

Hello Ben. "WOT"? Wot's that? The car'll be still under warranty so have you thought of taking it to the dealer to check?

[Benny No.1]

WOT = Wide Open Throttle. The cars booked in for its second service (37,000 miles) so i will let them know when it goes in, just wanted to know if anyone had any suggestions.

[M.O.S]

Could just be it needs a service... OR HT leads - have you changed them?

How long since the last service?

[TURBS]

It has no HT leads. The coil connects directly to the spark plugs.

[adam_Randell]

maybe you have a coil knackered....

[Benny No.1]

Well I hope the R56 ECU is clever enough to tell MINI this when it goes in! Or to tell them exactly what's going on. The are putting it through a full diagnostics because I have a stumbling idle issue as well.

[Tara&Paul]

Our's started misfiring while idling today, probably another "characteristic" of the car?

P.

[GEORGE-FEY&JUNIOR]

dear friends,
i face exactly the same problem as Ben, on my new R56 a couple of weeks now.i have done 9000 klm in total but during driving the car in a 'wot' mode with 3rd gear (3800-4300 rpm) i feel an enormous but instant jerk,and during 4rt gear at about 4000 rpm i feel a loss of power for some seconds.
unfortunatelly the check engine never lid so the people at mini garage don't know what to change!!
believe me it is very annoying and i have to say that i do not have any confidence to the car any more!!
please if somebody has any idea or even better a solution to this problem it would be very worthly!!!
thanks to all

[minky]

I have been expierencing the same problem, but couldn't out my finger on it. And sounds very similar to a misfire. I get mine changing up from second to third, and occaisionally what sounds like a thudding pop noise from the rear, I just though it may have been the exhaust note.

Hmm time to visit the dealer.

[Jimbo1989]

Just thought I would add myself to the list of this problem! has been happening for a while. It went in for a service, with me thinking that this would sort it out, but still the same problem. Also the car has started to develop another problem where it sounds like the engine is about to stall itself or cut out when just sat there in neutral not putting any revs on or anything! I dont know whether the two problems are connected or
completely different, but either way it is really starting to annoy me!

Any sugestions?!

[drichy]

Just to add a similar problem to the list! My March 09 Cooper S has developed and intermittant fault when starting from cold. Miss fires and sometimes cuts out completely - unless you put the accelerator to the floor and keep revving it hard. Trouble is it's not every time so of course it didn't happen when I first took it back to the garage. They then checked it out and said two of the coil sets needed replacing...and guess what? A day later and it did the same again! Took it back and they said the other two coils needed replacing.....two days later...same problem. They have now kept it overnight (as the problem seems to be when car has been stood for a number of hours) But they don't seem to know what the problem is (and I thought they were the experts being mechanics!!) but are going to change the spark plugs today! I'll wait and see what happens tomorrow morning! Anyone else had this problem???

[Robot Features]

Wow. I thought i would be the only one with this issue. Its happening everywhere. Mine is doing the same thing. Usually between 2200 - 3000rpm when the over boost is kicking in. Usually higher gears (3rd, 4th & 5th). I have brought it to the dealer twice. They reckon the ECU is fine and no fault codes have been picked up. They are now blaming fuel. I have never used cheap fuel in my car.

I'm about to write a letter to BMW. Not sure what this will do for me but its worth a shot.

Let me know if anyone has a positive resolution.

Regards

Mic

[Raul1976]

Quote: Originally Posted by Robot Features (original)

Wow. I thought i would be the only one with this issue. Its happening everywhere. Mine is doing the same thing. Usually between 2200 - 3000rpm when the over boost is kicking in. Usually higher gears (3rd, 4th & 5th). I have brought it to the dealer twice. They reckon the ECU is fine and no fault codes have been picked up. They are now blaming fuel. I have never used cheap fuel in my car.

I'm about to write a letter to BMW. Not sure what this will do for me but its worth a shot.

Let me know if anyone has a positive resolution.

Regards

Mic

Hi, my car did the same thing. The problem is you have carbon build up on the valves. This is caused by using normal unleaded fuel over a long period of time. It is not your fault - its just this car collects it more than other engines. This then throws the timing out but your ecu will not store it as a fault as the ecu advances or retards timing to account for issues. Buy BG44K on ebay. Fill up your tank and pop it in. It will de coke the valves and solve your problem. Don't buy anything else - including stp because it will not work. If you stick your car on the rolling road you will also find it is down on power. Use this stiff in conjunction with BP Ultimate. 97. They replaced everything on my car - sensors , vanos unit, etc etc and it never fixed the prob. Please report back results.

[Robot Features]

are you serious Raul? That is some F'd up stuff. How could an awesome engine with state of the art technology build up so much carbon within the first 3 years of its life?

Hmmm i was tempted to keep this car for the long haul.. but now i'm thinking twice.

New GTI comes out this week... might have to go have a look