I have a 2007 MC, it has about 87400 miles on it; for the past approximately 3 months. The car has been misfiring mostly in cylinder 2, sometimes 4. The car idles rough when I'm at a stop. I have already put new coils on 2 and 4, no change. I pulled the intake to see if i had carbon build-up, valves were clean. My latest effort, I changed the pre-cat oxygen sensor. This seemed to fix the problem for a couple days, but know its back to the same problems. I'm at a loss trying to find the cause of this misfire.

 

I'm assuming you also changed the plugs. How about a compression check. Possibly a bad or clogged injector? Just throwing out some ideas to check before throwing a bunch of unneed parts at it.

 

Ok, I'm getting frustrated. I took the car into mini for an engine diagnosis. They came to the conclusion, that the #2 fuel injector was leaking. Mini wanted 570$ to change it out, or 1200 for all 4. I pulled the injectors myself and sent them to RC engineering in Torrance to be cleaned. When I got them back, the car did run better. Couple days later the problem arises again, misfires in 2 & 4. I'm at a loss, any suggestions.

 

if your car is an S model they are having problems with the timing tentioners and can cause misfire issues and its just a good idea to replace it i have done quite a few of them and it as fixed no starts misfires and timing chain rattles

 

It's a non s.

 

oh ok i dont know off hand if the non s has the same motor as the s or not

 

I've been searching like crazy for answers to your first initial issue .. my 07 MCS with 53k (that I just bought 2 weeks ago) just threw a "misfire on cylinder 2" code this morning. I found this thread on here that seems to have a lot of useful information, and also other possible causes that you may be able to check on your MC. P0302 Cylinder 2 Misfire

Where can I find more information about this since I have the S?


I've got an 07 MCS with 53k that just threw a "misfire on cylinder 2" code this morning. Just purchased this car 2 weeks ago and have had zero codes until today. Idles rough, stutters at very low speeds (RPM's?) and also when trying to go open throttle (highway).

First thing coming to mind are the spark plugs, which I will replace this weekend anyways regardless of it being the problem or not. I've also been searching these forums extensively and read that the coils were another very common cause for misfire in the MINI's. Even if this is not the issue, would it be wise (considering the car is used) to just install new coil packs anyways? I think I'd like to, and then go from there.

Brings me to my question : I've searched online, everywhere that I could think of. I've read that aftermarket coils aren't entirely worth the amount of money and the stock ones are just fine. Any idea where I can find new OEM coils online?

 

Last night I swapped injectors 2 & 3, to see if the misfire moved with the injector. It did not, which makes me think it may be something worse.

 

Anybody ever do a compression check/leakdown? ( to try to pinpoint the issue as mechanical due to compression vs a sensor issue etc).
Any odd noises or sounds?
A non s should NOT have a carbon issue...different injection system than the S with direct injection.
Assuming this has been with multiple tanks of fuel from different places...and good octane.