Over the last few months I've read of frequent stories of the dreaded "carbon build up" issue related to VAG (VW/Audi) FSI (direct injection) engines, leading to significantly reduced performance and happens in less then 20k miles. This is widespread apparently affecting all FSI engines, from a golf gti/audi tt up to audi RS4. I have also read that it affects other cars with direct injection such as the N54 engines (such as the newer bmw 335i), and also affects some Porsche models which also use direct injection. From reading lots of the reports it is not due to the fuel grade that is used but an inherent fault where the fuel does not come into contact with relevant parts/components, as opposed to older designs where the fuel does come into contact with all relevant parts and cleans and prevents this carbon build up issue.
Anyway without going into more detail about the above (more info can be found here for those interested http://www.audizine.com/forum/showthread.php?336352-Audi-FSI-Engine-Carbon-Build-up-Megathread) does the S54 lump used in the Z4M use direct injection?
Anyway without going into more detail about the above (more info can be found here for those interested http://www.audizine.com/forum/showthread.php?336352-Audi-FSI-Engine-Carbon-Build-up-Megathread) does the S54 lump used in the Z4M use direct injection?