Maybe this is perfectly normal, I wouldnt know... my b-pipe had been leaking for so long, I finally got it replaced and am now noticing a drivetrain 'whine' since the cabin is now so quiet and peaceful. The car is a 1996 Honda Accord F22, auto trans with 93,000 miles. The noise itself is hard to explain, but most would describe it as a whining, and sounds in sequence with the vehicles acceleration. I've heard a similar noise while driving a RWD car, the rear axle will 'whine' so perhaps I am hearing the front drive axle? If I rev the engine in Park, I do not hear it... only when the car is driving, and the noise is most audible when the car is accelerating or coasting at around 45-50 mph. Its not really loud at all, but when the radio and AC are off, it can be easily be noticed. Btw, the sound has no relation to the whine you hear when going in reverse, its more closely related to the sound of a strong breeze. Sorry I couldnt be more specific, thanks for the help.