[PaiNFuLSeDaTiVe]

So, with my Cobb installed, I get misfires on 4 and 6. This originally started after running Stage 1+ with FMIC. I reduced it to Sport and it went away for a while, but came back a month or so later. It now does it all the time with the Cobb installed, but never has a problem at stock config. Took it to BMW for other problems (brake job/etc) and they couldnt find any problems with the coils/plugs since there were no codes being thrown or CELs. I know plugs were done 20k ago, but coils have never been replaced. I'm looking at coils as being the problem... Trying to get input of others that have had similar issues while under warranty to see what I should do. At this point I have left the Cobb uninstalled and keep praying to see a CEL at some point in time so I can get BMW to replace the coils... that $750 Cobb is burning a hole in my pocket though...

On a slight tangent - anyone got an idea what coils cost? I remember looking them up a year ago for my `07 and they weren't hella expensive, but weren't cheap either...

Thanks ahead for anything constructive criticism anyone can offer.

[Wookie420]

I'm getting a cyl 4 misfire code quite often too. I'm about to uninstall the tune to see if it happens running stock ECU settings.

[cmyk]

Have you had your intake valves cleaned? I wasn't seeing misfire codes, but was getting small "hiccups" -- and occasionally larger ones that really felt like misfires, but no codes being thrown -- with Cobb installed, running Stage 1 Aggressive + FMIC (mine also diminished or went away when Cobb was uninstalled). Had intake valves cleaned in December and the issue has not resurfaced. Coincidentally, cyls 4 and 6 were the nastiest looking IIRC.

Also, if you want to confirm a bad coil, reinstall your Cobb and swap coils on 4 & 6 with 3 & 5. If the misfire codes pop up on 3 & 5, there's your answer.

[PaiNFuLSeDaTiVe]

the guy who had my car before me actually had the walnut blast done before i bought it. Im too lazy to swap coils (lol) but I'm pretty sure thats it... if not, it'll just be bad plugs (but i doubt it after 20k, but you never know.) either way, i'd rather BMW pay for it since I have it covered. Thanks for the advice!

[Wookie420]

Originally Posted by cmyk

Have you had your intake valves cleaned? I wasn't seeing misfire codes, but was getting small "hiccups" -- and occasionally larger ones that really felt like misfires, but no codes being thrown -- with Cobb installed, running Stage 1 Aggressive + FMIC (mine also diminished or went away when Cobb was uninstalled). Had intake valves cleaned in December and the issue has not resurfaced. Coincidentally, cyls 4 and 6 were the nastiest looking IIRC.

Also, if you want to confirm a bad coil, reinstall your Cobb and swap coils on 4 & 6 with 3 & 5. If the misfire codes pop up on 3 & 5, there's your answer.

thanks for the info! no, valve cleaning job is on the horizon though.

EDIT: How much of a pain is it to swap coils?

[cmyk]

Swapping coils takes all of 10 minutes (half of which is tearing down the microfilter etc). You could just follow the spark plug DIY up to the point where coils are popped off

[PaiNFuLSeDaTiVe]

I did my plugs in my `07 and it was literally a 15 minute job. Considering you have to pop your coils off to get to the plugs, maybe 10 minutes? Pretty simple, just search for a plug DIY and you'll see.

[PaiNFuLSeDaTiVe]

Originally Posted by cmyk

Swapping coils takes all of 10 minutes (half of which is tearing down the microfilter etc). You could just follow the spark plug DIY up to the point where coils are popped off

LMAO JINX

[Wookie420]

awesome. thanks guys

[michael1284]

i've got the spark plug tool dan if u need it. i think like 10-15 ppl have used it since i've bought it...i've yet to use it still lol.

[E92M356789]

That happened to me as well and I changed the ignition coil and it went away.

[Imperator]

Originally Posted by PaiNFuLSeDaTiVe

I know plugs were done 20k ago

I've seen a good number of recommendations to change plugs on 20K intervals with a tune installed. I kept getting misfires on cyl 1 during cold starts, to the point where the car would stutter and illuminate the CEL at low loads. New plugs resolved that issue completely, no coil swaps needed.

[EPT535i]

I had the same problem. Changed my plugs and its gone. Runs way better.

[Wookie420]

Plugs are new. Coils are my next likeliest suspect.

[PaiNFuLSeDaTiVe]

Originally Posted by Imperator

I've seen a good number of recommendations to change plugs on 20K intervals with a tune installed. I kept getting misfires on cyl 1 during cold starts, to the point where the car would stutter and illuminate the CEL at low loads. New plugs resolved that issue completely, no coil swaps needed.

Tune hasn't been installed but maybe 2k miles. Pretty sure it's gonna be the coils, but still have plugs as an option. This issue only happens with the tune installed at WOT.