Originally Posted by 35mphgolf
I'm about to buy a 2011 335d - all these head rebuilds/engine failures due to carbon buildup is having me worried. Is there a DIY written on cleaning up your intake system and how to prevent additional buildup (oil catch can etc..)? Should I even be worried?
From posts I've seen this never happens on the X535d. Light engine loads seem to be the reason behind it. The 335d weighs less than the X5. Liqui Moly has some interesting products for diesel engines.