Let me startout by saying thank you for any help.I have only owned the car for about 6 months. Since the wheather has gotten a little bit chilly around here (below 40 ) i have noticed that when i go out and start my STS ( model year 1999) that a strange noise comes from the dash. The noise is coming from the lower left quadrant of the dash, quadrant starting under the steering wheel going up to wood trim and the all the way to the left. It seems to be coming from between the light beam controls and the steering wheel. I have also noticed it makes the noise even if the engine is not turned on. It never did this before the wheather got cold. Itgets to be really noisy if the defrost is turned on but after a while the noise dies down.

What the hell is this very annoying noise? if it is something that is not harmful i can live with it, but i can not simply ignore it until i know so. It has been my expierence that things, especially cars, make wierd noises for a reason. The noise sounds like a pretty small electrical or mechanical motor running.

Can anyone help?

thanks,

TS

 

Now that i think about the noise it kind of sounds like a really small air compressor running. Was speaking with a tech and i think he thought i was talking about the rear deck of the vehicle as he thought it was the CVRSS relay. As far as i understand the active suspension and motor are located in the rear of the vehicle, correct? The front of the vehicle is passive suspension correct?

TS

 

Most likely hvac asperator. It is located behind small vent in dash near steering column . It has little fan motor made to it. Little motor when bad.

 

Thank you for your information. I had the same problem on my 2001 STS. The part the was replaced in the car temp sensor was 25640104. Problem solved.

 

Yep its a small fan that pulls air over a temp sensor. If you pop the small grill off between stearing wheel and lights (i used a paper clip with a hook, be carefull its plastic) you will see the snesor. What I did to remove it was pop end of dash (part that has hole that seals to door for vent) and you will see it, its about 6 inchs long, sorta like a old pop bottle, one end is larger (fan end) and other is small (to vent in dash). If you look in you should see one bolt holding it in. get a 1/4 drive and long exstnsion and you can get it out (bolt), carefull not to drop bolt. Then you can work it out. I found if you take the center under stearing wheel (bottom of dash) off and then take the bolt on left of stearing wheel (still under dash) you can pull corner of dash down a bit to make it easier. Once you get it out (it does have some wires you need to unhook) you can pop it open, take a sharp pin/razor/ whatever and pop seal off back of fan. I took some marvel mystry oil and put a few drops in back, used my thumb to force it in, cleaned it all up good and put seal back on fan. then replaced in my car. Been 27 below here and almost 3 months and no sounds since. Heard part is around $60-100 if they have it in stock.

 

Appreciate this thread, as my 2003 SLS in cold weather for three years has been emitting a humming/buzzing sound. Because of this post, I decided to try it today. Popped off the small vent cover and dash driver's side panel. Got the device out, removed the tiny fan and lightly oiled and reinstalled. Quiet, like a Cadillac should be, once again. Thank you.