I have an august 03' build cooper S. About 5k miles on the clock I experienced a misfire. I pulled over, shut the car, counted to ten and restarted. The check engine light stayed on for around 3 key cycles and all was fine. A week later it happened again in the exact same spot near my home. A week later the same thing in the same spot. What I determined from that is the misfire is occuring when the car reaches normal temp. Since I have a nav. car with no gauge, I know from my other 2 cars that that point is where I would get to temp. Sometimes I can go 2 months with nothing and then it will happen 5 days in a row. It never happens at night, only when the car sits for an extended period.like overnight. It is not temp. related either, because it happened in the summer, and winter. Here are the stats on my car, and the steps I took to remedy the problem wich did not work:

(the misfire iscaused by the #4 cylinder on the fault code)

(I have installed on the car a Supersprint Race exhaust and Promini Intake)

I noticed that my coolant tank was leaking like everyone elses and coolant was spillling on the ignition wires. replaced the tank.............no more leaks but still misfires.

My dealer replaced the coil and ignition wires..still misfires.

we just today downloaded the lasted software into the car....pulled out of the dealership and it misfired! I have been dealing with this now for 36k miles and it is annoying the **** out of me! Can anyone offer up some advice or has heard of this problem?

Thanks.
Phil Danza

 

I didn't see that you replaced the spark plugs. It could be cracked and the heat expanding could cause a gap.

 

I've once have the same problem with my Olll Toyota corolla.... It misfired in the cylinder that has a water drip inside the sparkplugs chamber
solution:
take out your spark plugs(where it missfire)
clean the whole sparkplugs housing until it has no water left.... and make sure change that sparkplug....

it worked in mine...

let me know how is yours......

daniel-

 

Be careful, is it a misfire or backfire, if its a backfire dont drive it it will ruin the supercharger, if it is a misfire i woudl agree with the above ideas! it can be on of three things on a misfire, coil, wire, and/or plug........

 

Het Phil ,
Great to see u on the board.
I'll stop by soon to say hello and catch up :smile:

Unfortunately I personally do not have an answer for you....re: the mis-fire issue....
but a though is to ask the question to ....
Randy of WebbMotor Sports , Eric of Helix , and or Peter of M7....

There are others of course to ask...but this is a good start :smile:

Peace,
D :smile:



_________________
PM d-mini-ero

 

I'm with MINI USA. I've passed this message on to a MINI National Customer Relations Representative who will be in touch with you soon.

 

I've had the same issue. Drag, isn't it?

erik

 

I had a misfire a lil bit ago, codes said it was faulty fuel injector, it was still under warranty so i took it to dealer and they checked it out, swapped the injectors around to see if it was that exact one, it wasn't turned out being a wire going to that fuel injector had rubber on my intercooler and was grounding out. I also have a '03 with 17k miles.