I have a 2007 R56 with 110k miles. I had noticed that is was intermittently hesitating (blipping) at highway speeds. Changed the fuel filter. It was black and the factory seal sticker was still in place so probably the first time that had been done. Car started right up and idled nicely for 15 min after the filter swap. No leaks evident at the filter housing. Test drive went great on surface streets. On the second drive I noticed bad hesitation on take off from stop but it ran reasonably well at surface street speeds. I decided to test it on the highway and it runs great without the previous 'blipping', at least on that first highway test. Now, around town, the takeoff hesitation is very bad and it has a hard time idling. I have to work throttle to keep it going. I will be checking for codes, of course, but I am looking for any ideas about why this happens to an otherwise reliable vehicle after changing the fuel filter. All thoughts appreciated!

 

Where is this fuel filter you changed? The filter is in the tank with the pump. If the car has an aftermarket filter; it possible the additional filter is causing a pressure drop that is starving the engine. Have you tested the fuel pump pressure? The pressure should be 50 PSI with the ignition on and the fuel pump running. The test point is on the fuel rail on the passenger side.

 

@CFR56 ,

Double check your “Vanos” solenoid for dirt buildup on the screen.





Check screen for clog or buildup of dirt