2007 R56 hatchback 120,000 miles

CEL on, running rough. Code shows Cyl 1 misfire

Pulled the plug, looks normal -- plugs were new at 102,000 -- pulled the other three plugs to compare with #1, all look the same as far as carbon buildup. No oil fouling.

What next?

And if it's $2,000 I'm handing the title to the dealer and tell him it's all his.

 

Try swapping coils around, see if the misfire moves. If misfire moves, new coils and plugs. Plugs should only cost ~$10 each. Wouldn't cost much to just throw new plugs in it regardless. New set of coils would be ~$100. Swapping coils around would only take 10 minutes.

 

Check the fuel trim and AF ratio. Could possibly be the fuel injector. I hope it is not the dreaded crankshaft pulley.

 

YOU ARE A GENIUS!!!!!

My code reader showed MISFIRE CYL 1. I erased the code, swapped the coils between 1 and 3, CEL came on, code reader said MISFIRE CYL 3 !!!!!

Just ordered 4 coils and 4 plugs.

THANK YOU!!!!!!!

MERRY CHRISTMAS!!!!!!

 

New plugs and coils arrived for Rock Auto, took about 10 minutes to install new plugs and coils, Cooper is running like new!!!!

Thanks!!!

 

 

Congrats on fixing the misfire. With 120,000 on the clock, might be time to budget for a walnut blast of the intake valves, if the misfire returns. Three hours labor.