Strange noise under the dash

[Will308]

Recently i began to get a strange noise coming from underneath/behind the dash/steering wheel. It's not speed related, it's not steering related. It seems to be related to the heat/ac. It's hard to describe the noise, but it sound like a creak. It's a quick creak like you would get if you moved in your leather seats. It seemes to occure on a timed basis about every 15 seconds or so but I haven't timed it. I happens weather the engine is on or not, as long as the key is turned to the on position. When the engine is turned off, it will continue for about 2 or three times, much like the shutdown of the heat/ac system. That's what makes me think it's related to this system.
The car is a 1991 ,525i, M-50 non vanos, auto, 194,000 miles, with individual temp. controls for the passenger and driver.

My daughter thinks it's a little man in there who's only job is to irritate me while I'm driving. Any thoughts on how to get rid of him?

[Reidal]

A good question. I note a noise like you describe in my car immediatly after I turn off the engine.

I also think it has something to do with the heater. Possibly a controled vent of some kind driven by a temp sensor?

[632 Regal]

some noises are normal under there, you are right that it is related to the ac/heat. the doors are what you are hearing and I only get that on mine at shut down and occasionally with the ac on while driving. I think what you are hearing is in excess and maybe something along the ways is loose and leaking where the sensors are trying to compensate by opening and closing the doors...make any sence?

[Will308]

It just started doing it recently. I've owned the car since new and never had this happen. I was hoping that there might be some simple fix that someone has done before, like the LKM soldering fix.

BTW, My car is Calypso Rot also. '91 was the first year it was available and I fell in love with the color.

[Will308]

Thanks Jeff,
The climate control system does stay on for a while after I turn the car off. I've owned the car since new and as you said ,it shuts doors,etc. during this period and I am familiar with this sound.
This is something different. Might be a sensor? What's under there?

[632 Regal]

or youll get frustrated quickly.

[shogun]

I had a similar noise on my E32. Turned out to be the little fan blower on passenger side behind the glove box for cooling the E-box in the engine room. It has 2 speeds, low when you start the engine and a higher speed when a certain temperature is reached. It's the size of a pc fan. Had to replace it, abt $ 60.
There is another fan behind the IHKA control panel which circulates the air for controlling the temperature insde the car. This also sometimes makes noise when going bad, or sometimes it helps with simple cleaning.

[JonE]

Is the ac/heat system otherwise working properly? Losing coolant slowly? Could it be related to either the heater valve or electric auxialary pump? They're in the vacinity.

[Will308]

The system seems to be working properly.Today when i shut the car off there was a continuous clicking noise from the same area, that sounded like a switch being turned on and off very quickly. Almost a buzzing sound. The sound lasted until the a/c heat system finally shut down. It only happened once during several startups and shutdowns today. The constant creak ( the little man my daughter refers to) every 15 seconds is still there. Very strange! It's driving me insane.

[632 Regal]

i'm wondering if something is broken now. I dont know how the doors work weather its motors and gears or vacumm and cables but Ill bet somethings messed up. duh maybe you can look through your ETK and see whats involved and try to isolate it?