Spark plug Champion or OEM BMW

Stick with Champion plugs in the 4.0L inline 6. Anything else will have you chasing a “stumbling” idle.

I use champion on my 04. No issues. The more expensive ones that’s when the issues start

I use Champion in my 02. Never had any issues.

I’ve been running champion plugs for about 40k mi without issue.

I used champion spark plugs.. no problems here

If you are willing to put some money into it before resorting to drastic measures, try replacing all 6 of your spark plugs and ignition coils. Might help in your case, or it might not.

I won't run champion plugs in anything but lawn mowers. That's the only thing I've put them in that didn't get angry about it. Guess everybody's vehicles are different, but personally I don't think they're very good plugs.

Champion spark plugs are rubbish, not sure why they’re even sold.

I quit buying Champions 40 years ago for shitty quality.

Champion is garbage.