I have a 2008 4.8 (17K miles) & have had zero problems related to the engine (I have had an EDC sensor replaced twice, but that has nothing to do with the engine.)

Great engine from my perspective, lots of reserve power, very responsive. Gas milage is not so good (but I expected that.)

I have seen few engine related complaints in any forums (most are with the clogged/frozen drainage valve thing on the six.....but there are lots more of those out there & that engine otherwise gets good reviews by most.)

My only significant gripe is the lousy back-up camera (shared by all BMW owners as best I can determine......)

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2008 4.8i Mineral Green Metallic Sports Package, Technology Package, Cold Weather Package, Rear Climate Package, Premium Package, Premium Sound with iPod adaptor & Sirius Radio, Auto Tailgate, Head up display