humming sound at standstill not from engine! turn steering left or right noise increase.dealer replace alternator did not solve problem.guessing maybe power steering unit.also car idle at 500 rpm when a/c on idle at 750 rpm feels like car straining,drive like a bull dog on a leach!(very jumpy) any 545i owner have similiar problems please advise.

 

You're kidding, right? All e60's do this (humming). Your dealer actually replaced the alternator?

This is the car in sleep mode.

These cars do rev to that level though. Most cars do at 500 RMP, the e60s do at 750 for some reason (and I dont like it). You have to totally keep that break down hard.