key off 'whir'

[stx133]

When turning ignition to off, a electric motor 'whir' operates for about 2 seconds. recently it is starting to sound a bit sick.
a) what is it??
b) the battery was recently replaced and is good, if the 'whir' is starting to sound sick is it just loading up or is somthing about to go 'phut' and cost me money...

thanks.

[Sam-Son]

I have the same thing No idea what it is but it hasn't broken anything so I don't bother with it

[BMWCCA1]

Don't know if this is your situation but...
The E34 returns all HVAC controls to a default defrost position on power-off. Worst case when you start the car you'll at least have defrosters. The sound you hear is the servos operating the flaps. Try putting your car into the defroster mode before shutting off the car and see if that changes the noises you hear. The original E32s used to delay this reset for a few minutes, causing one of my customers to swear his car was chanting to him if he sat in the car in the garage for a while after turning it off. I suppose they changed that for the E34 based on such confusion.

[stx133]

legend

[EricB]

Timely post, as I was just scratching my head about that sound as well today.

[pundit]

When turning ignition to off, a electric motor 'whir' operates for about 2 seconds. recently it is starting to sound a bit sick.
a) what is it??
b) the battery was recently replaced and is good, if the 'whir' is starting to sound sick is it just loading up or is somthing about to go 'phut' and cost me money...

thanks.

This has been covered often and most still don't seem to get it.
There are several noises that eminate from behind an E34's dash.
There are the stepper motors that control the various vents.
These generate a fairly quiet whirr tick, tick, tick noise and often come and go for several minutes after switch off. You need a fairly quiet cabin to hear them.

The most obvious and loudest noise that generally occurs within about 10 - 20 secs of take off and shutdown is the windshield wiper arm pre-tensioner motor.



Here's an excellent link covering the whole thing in detail...
http://bmwe32.masscom.net/dutch740/wipertensioner.htm

This is a noisy beast and makes a loud whirring sound which can last around five seconds.
It will sound like it's coming from behind the instrument cluster.
If suffering from a lack of lubrication it will tend to sound more like grinding noise.
Passengers reqularly ask... "What's that noise?"
The wiper pre-tensioner motor is the noise most people query and the one most incorrectly diagnosed as climate control stepper motors.
Stick a screwdriver on the drivers side wiper arm spindle when it's operating and you'll hear it clearly.

I'm going to record these noises and post a link.

[Ferret]

The wiper pre-tensioner motor is the noise most people query and the one most incorrectly diagnosed as climate control stepper motors.

Was the E34 ever fitted with these? mine certainly doesnt have this system on it.

[myles]

It was an option on 530, 535 and 540 models. My 535 has it.

[pundit]

Was the E34 ever fitted with these? mine certainly doesnt have this system on it.

Although that link was for an E32 740 they are also fitted to E34's.

Here's a link to a U.S. Spec 535 E34.

Item No. 4 - "Pressure adjusting device"