Whirring motor noise behind dash shortly after starting and switching off?

[pundit]

I can't recall who I asked about this before but what gives with the 'gyroscopic' whirring type motor noise eminating from behind the driver's side of the dash? (RHD - 90' 535iA) It usually occurs just after I take off and lasts anywhere from 5-10 seconds. Then just as I shut the motor off after pulling up, it does it all again. I'm stuffed if I know what it is. My guess is some kind of motorised vent opening or closing? - What's the story?

P.S. I've ordered a Bentley manual.

[simon-york]

It is just the stepper motors for the vents - they all do it. Not a problem just normal activity for your E34.

[632 Regal]

that sound freaks out small children

[Kalevera]

Jeff - it freaks me out, too

[ScottyWM]

They don't go into BMW's yet though. Ours go to visteon, Delphi, and Valeo, some go into Jags & Mercedes. If we made any that were even 1/10 as loud as the ones in bimmers they'd reject them and get another supplier. They have to meet certain low sound pressure levels. Jaguar is the worst - they actually will sit with the engine off, power on, put their ears to the dash, move the flaps, and if they hear ANYTHING they don't like they give us hell.

Personally I like the reassuring sound that tells me they're working!

[Paul in NZ]

i dont know if the stepper motors is it.My car has the electric motor that regulates the windscreen wiper pressure.mine makes a whiiiiiiiirrrrr as i move off(about 15 kh hr) and when it turn the motor off. and you alsohear it sometimes wheh you wash your screen.It definetly comes from the far right of the dash.....The ventilation motors are different esp on our cars pundit.When you have 5 minutes to spare on a quiet quiet night stay in your car for five minutes after you shut it off.....it whirs and creaks and buzzes for AGES......

[DueyT]

Germans like to hear things work in their "driving" cars. Re: Jags...if you can't hear it, how do you know it's working?

[Tcdoe]

This one is driving me . I'm sure it has something to do with the speed sensitive wipers.. Is there really nothing that can be done about it? I can live with the short creak/buzz when driving off, but it's the wiping and turning the engine off that bugs the hell out me. Lately it's been going , it starts making modem sounds out of the blue when driving with the wipers off, then if I touch the wipers it really freaks out. Sometimes when I turn the engine off it's really really loud. I won't accept this, theres gotta be something to be done?

Edit: Btw, there's no air conditioning in my car.

[pundit]

This one is driving me . I'm sure it has something to do with the speed sensitive wipers.. Is there really nothing that can be done about it? I can live with the short creak/buzz when driving off, but it's the wiping and turning the engine off that bugs the hell out me. Lately it's been going , it starts making modem sounds out of the blue when driving with the wipers off, then if I touch the wipers it really freaks out. Sometimes when I turn the engine off it's really really loud. I won't accept this, theres gotta be something to be done?

Edit: Btw, there's no air conditioning in my car.

I originally started this thread and I'm now convinced it is the stepper motors for the climate control. Yes it is loud, and if I get home late I'm sometimes certain it must wake half the neighbours in the street. I guess I've just come to accept it as being all part of the rich tapestry of owning an E34!

[Tcdoe]

Yeah, I too got used to it pretty quickly, but the sound used be more of a nice beep earlier. Recently it's developed into this rough cracking buzz, kinda hard to describe. That too would be fine if it just did it when driving off and switching off, but now it does it randomly and sometimes it keeps doing it for 30 seconds. That just CAN'T be normal.