I've been enjoying my 2005 X5 4.4i sport for over a year now and recently encountered a problem. When I parked it 10 days ago in the garage it was running fine. When I fired it up to drive the other day, it was missing and running rough. The "service engine soon" light came on so I thought I'd take to my local indy (independent) shop, Bimmer Haus in Broomfield, CO.

It turns out it was randomly missing on 4 of the 8 cylinders. The shop put in new NGK plugs and now it is running like a Swiss watch again.

Just thought I'd pass along experience so other might benefit.

-DR