Hello, my 20 year old 3 series estate (E91) has 93,000 miles on the clock. There are no codes detected at a BMW specialist's garage but there is a slight but noticeable stutter on acceleration. It happens when the engine reaches 2000 rpm in all gears. The vanos solenoids have been replaced, a new fuel pump fitted, new ignition coils and spark plugs. All the injectors have been cleaned and tested. A smoke test for leaks has been done-none discovered. Can anyone think of any other checks that can be done without breaking the bank?
