BMWNA has just issued a statement regarding the turbo lag issue that some of you might have noticed with your 3.0 twin-turbo engine(N54). I am one of those people that noticed an issue with the engine, but when I took my car to the dealership, they couldn’t find anything wrong with it.
I’m glad they finally acknowledged the potential issue and that measurements are being taken.
“In an effort to address specific noise concerns, BMW updated the turbocharged engine software on 335i/xi and 535i/xi models built from June 2006 through March 2008. The updated software causes a small amount of increased “turbocharger lag” under certain circumstances and, while not substantial, the lag may be perceptible to the most sensitive BMW drivers. X6, 135i, and 3 Series/5 Series vehicles from March 2008 production onward are not affected.
Release of the new software to restore the original turbocharger response is planned for January 2009, and it will be available for vehicles produced from September 2007 through March 2008 when they are brought to an authorized BMW center for a repair which requires a programming update. Clients with vehicles produced from June 2006 through September 2007 may request installation of the January 2009 software update.
Clients who get this update should understand that there is a possibility of slightly increased engine noise levels under certain circumstances.”[Source: Bimmerfile and BMWCCA]