e320 2003 200,000 + miles. Great mpg 32 highway 28 around town. Had valve cover gasket replaced. MPG now off by 3 to 4 miles per gallon? Any input? Thanks
Does the PCV valve go in to the valve cover on your car? If so, in changing the covers the PCV valve may have been improperly reconnected, resulting in a vacuum leak and cause precisely what you describe
Search Mercedes-Benz E-Class Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Mercedes-Benz E-Class Experts