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 :D

[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? :D

[Tcdoe]

This one is driving me crazy. 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 crazy, 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 crazy. 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 crazy, 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! :p

[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.

[shogun]

There are:
the stepper motors and the flaps. If it cracks, the flaps could stick or a stepper motor holder is slightly broken. Common problem. It should just "flap" and whirr, that is all. Go on my website to Johan and Sean's page and look for center vents. There the broken plastic holders which are broken are shown. Difficult to replace them. The upper part of the IHKA must be replaced. Some people tried to re-inforce these plastic holders.
Then there is the ADV pressure motor for the wipers. That can also be defect. Also a nice info on Johan's page.
In addition there is a small motor behind the IHKA control panel for the air temp sensing inside the cabin, and (on some) models another motor for feeding air into the E-box on the right side of the engine room. That motor is in the E32 (maybe not in E34, you have to check). It sits behind the glove box. And when it is defective, it makes all kinds of noises from chirping like a bird to sounds that you believe your car will break down soon. I changed the one behind the glove box last year. Costs abt. 65 $.

[BigKriss]

pundit - i hear the same whirling noise as you after switching off the car. It does seem unsuall at first. I just lived with it.

[Paul in NZ]

i am sure its the adv......the stepper motors are the ones that work away for ages afterwards....almost inaudible you just hear quiet whirs and slight creaks for abot 10 minutes!

[Tcdoe]

Paul: I agree, it's definately connected to the wipers.

I think my stepper motors are ok, I've never heard any noise from them.

shogun: Thanks for the help. I may be blind, but I just couldn't find any info on the adv pressure motor Johan & Sean's page. Only about the wiper tensioner and mechanism replacement.

[shogun]

Wiper tensioner as they call it on Johan's page is ADV.
You can check it: remove the relay for the ADV or tensioner under the rear seat. If noise is gone. It was the ADV.
http://shrubbery.student.utwente.nl/dutch740/wipertensioner.htm

[Tcdoe]

Wiper tensioner as they call it on Johan's page is ADV.
You can check it: remove the relay for the ADV or tensioner under the rear seat. If noise is gone. It was the ADV.
http://shrubbery.student.utwente.nl/dutch740/wipertensioner.htm

Oh, stupid me.. I was assuming it was some kind of small electric motor inside the dash, because that's where the noise seems to be coming from. Thanks again :)

[Tcdoe]

Wiper tensioner as they call it on Johan's page is ADV.
You can check it: remove the relay for the ADV or tensioner under the rear seat. If noise is gone. It was the ADV.
http://shrubbery.student.utwente.nl/dutch740/wipertensioner.htm

My Bentley manual is still in the mail (wonder if customs took it..)
so any tips to identifying the right relay would be greatly appreciated.

[pundit]

Wiper tensioner as they call it on Johan's page is ADV.
You can check it: remove the relay for the ADV or tensioner under the rear seat. If noise is gone. It was the ADV.
http://shrubbery.student.utwente.nl/dutch740/wipertensioner.htm
I'm surprised if this is the noise I'm hearing. I would have though the tensioner would only operate with the wipers being switched on. Why all the fuss with the wipers off? I'm still thinking it's something to do with climate control motors resetting themselves... still I maybe wrong?

[shogun]

It is a motor, and it starts with 15 kmh and it is somehow linked with the speed senor signal somewhere, if I remember right.
Would have to look into the drawings.

Pundit, that thing was designed for high speed Autobahn driving with more tham 200 kmh.
And for such purpose it is a wonderful thing, I can tell you from experience when I still lived in Germany many years ago, when Autobahn's were not yet so crowded.
The drawing is on my website under ZKE>ADV
http://tridem.han-solo.net/auto/erich/zke/image043.jpg
The motor
http://tridem.han-solo.net/auto/erich/zke/image047.jpg
impulse wheel for ADV
http://tridem.han-solo.net/auto/erich/zke/image049.jpg
and the diagnosis in case of faults
http://tridem.han-solo.net/auto/erich/zke/image053.jpg

[Tcdoe]

I made a short video of the noise. Click here (1.6mb) (http://www.saunalahti.fi/pihled/noise.avi)

Is this what you guys are hearing?

[Paul_540i]

Sounds like mine too. Does it when you move off, but to check for sure try this: Start the engine and use the windscreen washers without moving. It will apply the pressure so the washers work properly even though the car isn't yet moving.

I also notice that if I've been driving at high speed (100+ MPH) it will whirr for much longer when I switch off, indicating that more pressure was applied during the high speed driving. Surprisingly it must maintain that pressure even during later low-speed driving, is this normal?

Does anyone know the point in this system? Why not just apply sufficient pressure at all times which is what every other manufacturer seems to do.

[632 Regal]

ever go to a car wash and it blows the wipers off the windshield? same thing happens at 150mph.

[pundit]

I made a short video of the noise. Click here (1.6mb) (http://www.saunalahti.fi/pihled/noise.avi)

Is this what you guys are hearing?
That's it! But mine lasts about three times longer.

Okay I now realise there are three different noises that occur. I believe the loudest noise, and the one most are discussing, is the wiper tensioning motor. I checked last night by placing my hand on the wiper spindle as I shut the motor off and I could feel something was definately going on with the wiper system. The other various noises appear to be the vent motors (not as loud and more random) and what I believe are the heater valve solenoids.

[pundit]

Sounds like mine too. Does it when you move off, but to check for sure try this: Start the engine and use the windscreen washers without moving. It will apply the pressure so the washers work properly even though the car isn't yet moving.

I also notice that if I've been driving at high speed (100+ MPH) it will whirr for much longer when I switch off, indicating that more pressure was applied during the high speed driving. Surprisingly it must maintain that pressure even during later low-speed driving, is this normal?

Does anyone know the point in this system? Why not just apply sufficient pressure at all times which is what every other manufacturer seems to do.
Yeah, I don't understand the point either. I would have thought either just use a higher force all the time (maybe too much load on the wiper system under normal operation?) or just apply more force based on road speed. Maybe it does this anyway as you suggest. The higher the speed, the greater the force. Though I don't know why it seems operate even with the wipers switched off? Makes you wonder what other car manufacturer has an entire thread devoted to a windscreen wiper tensioner 'whirr'? :p

[Tcdoe]

That's it! But mine lasts about three times longer.

Mine's usually longer too. Actually the longer I drive, the longer it does that when shutting off.

[Randell]

i get a similar noise to the one in the video, it goes for longer and sounds like an automatic electric aerial extending just as i drive off after first starting the car, and then it sounds like it's retracting when i stop... the length varies and sometimes it doesn't make the sound at all... as there is no electric aerial i always assumed it was the windshield squirter pump or something

but then again there are so many odd sounds coming out of my car i've trained myself to ignore them all...

[Paul in NZ]

na na naaaa na naaaaa told ya.....it is odd but the wipers on this car are awesome..the very first weekend i got the car we were caught in a rainstorm/windstorm..I tell ya EVERYONE was pulling over and i could not figure out why my vision was not perfect but i could see very clearly at 80km hr...i beleive that only he early cars had this system Sometimes you also here it at odd times say when you wash the screen during a dry drive.....

[Paul_540i]

Mine's a '95 and it has it.

[danzee]

writhing at the vision of their Bangleized spawn