VTG/Transfer Case noise - NO triad of lights - actuator gear, TC fluid replaced

[bourneusa]

Hi, everybody.

So, I've had a 2004 E83 2.5i for about 6 months now. When I bought it, it had the telltale transfer case/actuator symptoms of the buzzing noise when ignition is turned off, accompanied by the triad of lights. Now, I've done a lot of reading on this and I have reasonable repair skills, so I didn't hesitate to buy the car as-is for very little money. The car had under 60Kmi. and was cosmetically perfect, so I bought it.

When I went to pick it up, the car wouldn't start. I quickly found that the battery was swimming in water after a very heavy rainstorm the night before. I drained the battery well, got the car started and took it home and I proceeded to tear apart the back of the car to find the parts which had been water damaged and to clean out the moonroof drains, which were seriously clogged with pine needles. Long story short, after first replacing the existing battery and making sure all electrical connections were clean and sound, I found (via the DIS application) that the VTG control module, just forward of the battery well, was completely fried. Found a used part, identical P/N, installed, swapped out the actuator gear (to address the buzzing noise at shut off, so I thought), and drained and filled the TC fluid, cleared the VTG fluid wear error, per all I read about potential issues with the VTG system. No more triad, but still the buzzing at shut off.

I can't find any reports of the buzzing noise upon shut off with no error lights. Is this noise ONLY present when there is an actuator problem/failure, or is this noise typical in the absence of any errors? We drove the car through the snowy new england winter with no problems whatsoever. It was a beast in the snow, actually, so I don't sense that there's a drive problem, but the transfer case/actuator noise is consistently present when I turn the car off. Usually two buzzes, sometimes only one, then it sounds like the motor responsible for the noise shuts off. It's similar to the noise that VTG calibration, using DIS, makes.

This is my first BMW, so I'm not sure if this is at all normal. Any advice would be appreciated!

-Jason

[MarkJWT]

This may be a silly answer, but are you sure the buzzing is coming from the TC? My CD player makes a buzzing sound when I switch off