2009 R56 Base

I have a skip now and again. I'm not throwing any misfire codes, but am getting a P0420. I do suspect a weak coil or coils.

I understand that a P0420 may result from unburnt gas.

Recently, when the skip was more pronounced, I gapped the plugs and swapped one of the coils with another and the skip went away for a while.

I'm going to test the coils with a gauge that checks how far the spark jumps. Three of the packs have 230,000 miles on them.

If I decide to replace any or all packs, any recommendations on the most reasonably priced dependable coils?

Any other advice on my situation is welcome.

Thanks!

 

The N14 motor uses coil on plug. There is no coil pack. You can tell the difference as there is not a set of long spark plug wires coming from a coil pack to each spark plug.

 

Thanks. I was aware of the coil over, but used the wrong terminology. I've edited my post.

 

Takes four coils and i do them all at once. I had one go bad then the next one went oems are delphi. They can stand the heat cycles and fail. I have the Bav Auto ones on my N14.

https://www.ecstuning.com/b-bavarian...t-of-4/5005kt/

 

I hang on to an old one that was good in my tool bag in the trunk. Didn't want to be midway between OH and WI and have one go bad in the middle of BFE. Other than that, I agree, when replacing, replace all 4.

 

An '09 Base cooper is an N12 engine.

OEM coils are Eldor not Delphi. I've tried Delphi coils and the get stuck in the cylinder head. AutohauzAZ had the best price on them the last time I checked.



Do you have a scan tool that displays live data? If not, you'll need one. Connect it via OBDII (not under the MINI menu), and look for your short term and long term fuel trims. Report back with your numbers at idle, 1500 RPM, and 3000 RPM.

 

Delphi are now coming through 'Made in China'.

Bosch aftermarket are rubbish, sadly.

Eldor's next on my list, when it's time again.

t

 

Pretty much everything is coming from China now. I just installed OEM Mahle pistons in my N12 and yep ... they came from China.

 

Correct, Cooper S/JCW is delphi, i was thinking Cooper S : https://www.realoem.com/bmw/enUS/sho...05#12137575010

Cooper is still eldor (a couple revisions later) revisions and they now how metal sleeves and made in turkey, just checked stock.

They have been jumping around with suppliers on these as they are a high fail an they have redesigned multiple times. Latest in the cooper S is a triple layer design with a metal sleeve. Also the plugs are now moving towards champion of france as they have the contract now for the plugs on BMW group.