2004 MCS Traveling to work the other morning the car started misfiring,clearing up, then misfiring again. I work about 35 miles from home, and by the time I reached work the car had a constant misfire. Borrowed a code reader from a friend in my club and it said #2 cylinder misfire. Replaced all plugs and wires and even coil, cleared code, restarted car and same condition. Anyone ever experience this before. I know my way around under the hood and am very skeptical of dealers - very difficult to find someone who is on their game. Any help would be greatly appreciated.

2004 MCS 15%pulley,CAI,Nology wires,Iridium plugs

 

I would use a fuel system cleaner kit (but do not attempt to clean the throttle body!). The valves can have build up on them and this may help. A lot easier than removing your head,unless you have that kind of skill/time. Also a compression test and leakdown would not hurt. Don't always distrust dealers. Find a tech that you can trust at a dealer.

 

do the compression test. i had this and it was a coil but not in your case . some have posted in the past on this and it has been a burnt exhaust valve . good luck .

 

Injector? Try swapping the injector in cylinder with the miss with another injector and see if it moves to the other cylinder. Code reader should show another cylinder misfire. Code reader probably wont show miss immediately, run engine for a while.

 

like posted above you can swap the injector to another cylinder and wait till the light comes back and see if it moved. also do a compression test and compare between cylinders. you should have at least 150psi on all cylinders.

if a compression tests shows low compression, then you can do a cylinder leakdown test to find where its leaking from. good luck!

 

So what was the diagnosis? Curious because I've got an 04 MCS w/ the same #2 cyl misfire. Just replaced coil, wires, plugs...as well as a complete valve job w/ new seals, seating & a Cometic head gasket w/ ARP studs beforehand. So I'm thinking injectors or god forbid oil leaking into the combustion chamber fouling the plugs due to worn piston rings or cylinder walls... I thought the valve job would take care of this when I had the same cyl misfire before. Waiting to hear from my tech as I post...

 

What did you find?

My 04 starting sputtering like crazy the other day when I threw it into 2nd gear. Lost all power, too. Ended up making a u-turn and driving it back home in 1st. Restarted the car a few times. Starts perfectly, 1st gear runs great, 2nd gear, awful.

 

Didn't post earlier 'cause all I can really offer is sympathy. Had a friend w/ an 05 6 speed auto (NO track time) w/ the same symptoms. Turned out to be valve guides that wore out like mine (even tho mine were SI aftermkt valves) And of course opening up the head is 10 hours labor not to mention whatever parts need replacing. But if it's valves then the seals & seating need to be replaced as well. NOT pretty. His was still under warranty - mine was not! After all the work I had done on post #6, a rocker arm broke on the test drive!!! So now I'm broke but happy...I.E. "It lives!!!"

In your case, however, it COULD only be plugs, wires, coil or injectors which would be MUCH better news! Good luck...Hope it's cheap!

And I'm really hoping this valve thing is not some inherent engineering flaw that starts showing up like some epidemic in the R53s just as they get out of warranty!!! The reason I say this is, when my friend described the various symptoms to the local MINI SA, he offered that possible diagnosis for the valves right off, which means he was definitely "familiar" with it!...

 

I let the car sit for a couple of days and now it works. I popped open the CAI and found the foam filter to be soaked, and had a slight build up that looked like wax. Maybe water was getting into the engine from here. I cleaned the foam really good and now the car runs like a champ. I'm going to have to get everyone's input on how often to clean these things. I feel like I cleaned it just a few months ago.

 

Oh, and a day later after driving it with the clean filter, the SES light has turned off. YAY!

 

Odd that it was "soaked". Never had that happen. Perhaps from cleaning the engine compartment at the carwash? (shrug) Anyhow, I clean my Alta foam filter w/ dishwashing detergent repeatedly, massaging it in & dunk rinse it in a bucket w/ running water. After drying, you apply oil spray that Alta has in their cleaning kit. (I always run out of their spray cleaner in the kit first & use detergent till I run outta the oil.) BTW, I'd say cleaning it every few months is a good thing, at the very least!

 

I had a missfire in cylinder #3 today. The power in the coil is low too. The guys at Autozone checked the codes. I need a new ignition coil, it should be here from the dealer on friday. After restarting the car, all seems well. The Autozone guys said not to drive it too much untill the part is replaced.

 

Did you get a SES light, though. And has it turned off since then?

 

It turned off after they read the code. I assume they reset it. The car runs fine, but as I said, I'm not going to slam it untill I get the new part.

 

My #3 terminal is corroded, and sometimes idles rough but nothing while driving. I sanded it clean with emery cloth, but its dirty again. Its clearly pitted from arcing over a long period of time. Next time something breaks I will bring it up and let the dealer replace it. Very odd.

 

My situation may be the same as your, and it's finally fixed!

This only happened when the car had been sitting for more than 6 hours, in any weather and driving conditions.

Drive about .5-2 miles and the car goes into limp mode--check engine and traction control lights on, no boost, (I put a guage in the air vent), and the exhaust note sounds terrible, (I have an Invidia and rear seat delete).

Dealer was able at one time or another to diagnose a "random misfiring" problem but unable to fix it. They finally engaged MINI USA and they determined it was...drum roll please, the fly wheel. Yes, the fly wheel, they said it has a spring and was out of balance or something?

As when you cross an elephant and a rhino, elephino if that was true, but I'll say the car is running fine now after two weeks of over six hour starts and HARD driving, (as usual), I'm a spirited driver and take this car to the track, too.

BTW, I've put the same, non-ethanol gas mostly the whole time, except when I switched to appease them, and then switched back.

Not sure if this helps, and good luck with your own situations!

 

I have a new to me 06 MCS with 20K and standard transmission. I get a sumble, misfire (yes I searched first) but only at low load and 3000 to 3400 rpm. I read the posts about the surge and yo-yo problems but they don't seem to match my problem. Any suggetions would be great.

Thanks,

Bruce
BSG06MCS

 

Did the new OEM Coil fix your misfire issue? I'm having the same problem from 2k-3k rpm, mostly when the weather gets really hot. I'm not sure to replace my coil pack and/or my plug wires, or maybe both. What do you recommend?

 

Yeah, the new coil has been working great ever since. At the time, I kept my after market wires, but I reverted back to my stock wires after my RMW tune. The insulation on one coil side boot was split.

Changing the coil is a 10 minute job.

 

Bump...I have a misfire issue as well on my 05 MCS. However I get the code of multiple cylinder misfire. It does not tell me the exact cylinder...I also get a code referring to the throttle body...I looked at the connection from the wire harness, and it was connected. Looks fine...I have the alta intake, but that has never been an issue. I took out the plugs, and the were extremely charred! Just black and cruddy...Could the throttle body cause a misfire!? From what I have been reading, it seems like it could be coil,valves, or injectors...Lets hope its not the valves I have an aftermarket coil and wires too....Any ideas!? Other wise im going to buy new coil, plugs, and wires...Thanks people!