Last week my E46 2001 (Y) 330d touring auto developed a fault, firstly i noticed a humming from the front passenger footwell area and also when i put my foot down the car would accelerate up to around 4k where it would almost seem to hit a rev limiter and not want to change gear, with no warning lights on dash lit up.
I did some research online and found the problem could be my under floor fuel pump so i replaced the pump (pierburg) and filter (mann) this seemed to clear the issue.
However, i went out in the car today and the issue has returned. Again i put my foot down and it seems to hit a rev limiter and not want to change up a gear, normal driving the car changes fine. I've also noticed some humming again from the passenger side again.
Recent work includes;
New EGR and main stat + coolant change
New Mann air filter
Oil + filter change (castrol/bmw genuine filter)
Changed crankcase breather from loo roll to vortex type