overhead console hum
Guest
Posts: n/a
overhead console hum
in my coupe when parked and the key is out, I can hear a humming coming from the overhead console. I know there is a little vent or something up there oposite the sos button, but I thought it was for the climate control. This seems to run all the time. Any ideas?
Member
Joined: Nov 2001
Posts: 130
Likes: 0
From: Alexandria, VA
C230 Sport Coupe
I don't have teleaid, and I hear a hum after pulling the key out of the ignition too. I always assumed it was coming from the ventilation system - though I don't know how I came to that assumption.
Guest
Posts: n/a
my particular sound is coming from the overhead console area. Even after several hours of sitting the car still makes the noise. Regardless of conditions ie; door open or shut, key in or out. I still want to believe it's part of the climate control but not sure.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
Benzo, I've noticed a slight hum in my C240 also when everything is shut off, but I've never really localized it. It's very slight. I'm wondering if your clue might be right. The little "vent" you see near the SOS button is the TeleAid microphone, I'm pretty sure. The only climate control sensor "inlet" I've noticed is on the climate control panel itself, you'll see a series of vertical slits in the center of the control. I've also thought it was some type of amplifier noise, but it's interesting that o2bsurreal hears it too w/o TeleAid. Wonder if it's the same sound. I'll try to listen more carefully to where it's coming from.
MLESKOVAR:
There is a pump that pumps the coolant back into the reservoir when you shut off the engine. You can usually hear it run for maybe 4-5 seconds. Had that on my Passat also. Also, it turns on if you activate the "rest" function on the climate control after you shut off the car. It's a louder noise than the one I think we're describing and it definitely stops after a few seconds.
MLESKOVAR:
There is a pump that pumps the coolant back into the reservoir when you shut off the engine. You can usually hear it run for maybe 4-5 seconds. Had that on my Passat also. Also, it turns on if you activate the "rest" function on the climate control after you shut off the car. It's a louder noise than the one I think we're describing and it definitely stops after a few seconds.
Trending Topics
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
Originally posted by benzomonterey
possibly I am incorrect but I thought the Tele aid microphone was the black circular one. I also have a small slotted vent like thing next to it. I will try to take a pic of it tonight.
possibly I am incorrect but I thought the Tele aid microphone was the black circular one. I also have a small slotted vent like thing next to it. I will try to take a pic of it tonight.
MB World Stories
The Best of Mercedes & AMG
7 Craziest Things AMG Gas Ever Built
Verdad Gallardo
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know
Verdad Gallardo
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
Admin Alumni
Joined: Nov 2001
Posts: 8,143
Likes: 19
See Garage
Originally posted by young
is that the audiopilot microphone?
is that the audiopilot microphone?
What are you guys doing to make your cars hum? My C320 doesn't hum (from the overhead console). Haven't you heard? BMW's hum! BMW's are the ultimate humming machines...
"Your manual is your best friend."
Amended 1/8/02 7:54 CST... Ooops, wait a minute... Uh, yes, it DOES hum, veeeeery slightly (you have to put your ear close to the console to hear it). Sounds electronic to me. My guess is a pre-amp for the various microphones. Or could it be a hum from the dash we hear at the console, directed up the windshield? I wouldn't think it's ventilation related. There are no ducts leading up the A-pillers to the console area, right? In any event, it's not going on my dealer to-do list... I'm not going to lose any sleep over this one. And to think my MB didn't hum like a BMW...
Curious? do non-teleaid equipped coupes still have the black teleaid microphone? You would still need it for the cell-phone package, yes?
Last edited by MB-BOB; Jan 8, 2002 at 09:21 AM.
Guest
Posts: n/a
I am proud to say that I am a manual reader 
and that I searched high and low for a description of the slotted beige thing. Even in the coupe pics I couldn't find it in the descriptions of the overhead console.
I wouldn't mind a slight noise but mine sounds sort of like a fan on low speed if you are just sitting in the car with nothing running. Oh well. It also appears by my email that MBTech attempted to respond but his post didn't work. So I guess the mystery remains.
Happy Motoring
and that I searched high and low for a description of the slotted beige thing. Even in the coupe pics I couldn't find it in the descriptions of the overhead console. I wouldn't mind a slight noise but mine sounds sort of like a fan on low speed if you are just sitting in the car with nothing running. Oh well. It also appears by my email that MBTech attempted to respond but his post didn't work. So I guess the mystery remains.
Happy Motoring
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,148
Likes: 16
From: Berkshire, UK
2004 SL55, 2015 A250d, 2016 GLC250d
The temperature sensors for the airconditioning have little fans in them to circulate the air (otherwise the air wouldnt go into there to me measured) - if you put a 1cm by 1cm piece of paper over one of the temp-sensor vents it will be sucked onto the sensor and wont fall off - if the fan is working properly -.
I dont know where the sensor is on the C class, but it sounds like you (a) may have found it and (b) the fan in it may be noisy ...
I dont know where the sensor is on the C class, but it sounds like you (a) may have found it and (b) the fan in it may be noisy ...
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
Tried it, it's true!...
Originally posted by Richard
The temperature sensors for the airconditioning have little fans in them to circulate the air (otherwise the air wouldnt go into there to me measured) - if you put a 1cm by 1cm piece of paper over one of the temp-sensor vents it will be sucked onto the sensor and wont fall off - if the fan is working properly -.
I dont know where the sensor is on the C class, but it sounds like you (a) may have found it and (b) the fan in it may be noisy ...
The temperature sensors for the airconditioning have little fans in them to circulate the air (otherwise the air wouldnt go into there to me measured) - if you put a 1cm by 1cm piece of paper over one of the temp-sensor vents it will be sucked onto the sensor and wont fall off - if the fan is working properly -.
I dont know where the sensor is on the C class, but it sounds like you (a) may have found it and (b) the fan in it may be noisy ...
I tried the paper test as suggested, and sure enough, the overhead console "vent" (sensor) we're describing indeed holds the paper in place due to the fan. Same with the small vent on the climate control panel. I also discovered that with the ignition off, only the fan in the overhead console continues to run -- I guess constantly. The one on the climate control panel stops (paper fell). I wonder why the upper sensor fan runs all the time???
Benzo:
My fan noise is very faint and hardly noticeable. If yours sounds loud, there might be a problem. ( I do have a C240 but I would assume yours is the same).
Admin Alumni
Joined: Nov 2001
Posts: 8,143
Likes: 19
See Garage
Originally posted by Richard
The temperature sensors for the airconditioning have little fans in them to circulate the air (otherwise the air wouldnt go into there to me measured) - if you put a 1cm by 1cm piece of paper over one of the temp-sensor vents it will be sucked onto the sensor and wont fall off - if the fan is working properly.
The temperature sensors for the airconditioning have little fans in them to circulate the air (otherwise the air wouldnt go into there to me measured) - if you put a 1cm by 1cm piece of paper over one of the temp-sensor vents it will be sucked onto the sensor and wont fall off - if the fan is working properly.
Mine seems to run at a slower speed when the motor is off (since the paper falls), so if the hum is pronounced on your cars, maybe the motor is (stuck) running full blast all the time. (My clim. cont. is set on auto at the moment, not EC mode)
Well, we're learning something new every day. Thanks, Richard. Now, I'm wondering where that audiopilot microphone is. Could it also work off the teleaid/cellphone mic?
MarkL, you beat me again, Bud! (5-minutes) LOL!
Last edited by MB-BOB; Jan 8, 2002 at 02:24 PM.
Member
Joined: Nov 2001
Posts: 139
Likes: 1
Could the fan still be running due to the car being left in the "rest" mode that I read about. There is the feature to use residual heat to keep the car warm for some time after the engine is shut off. If this feature is set would that cause the little fan in the overhead to keep going as well?
John R.
John R.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
No, I don't think so. Read below. My car was off without the REST function running.
MB-BOB:
I also did this at lunch time. I knew if anyone checked it, it would be you! After I had parked the car for about 30 minutes at my house, I checked the overhead sensor fan again with the small piece of paper before I started up. The paper still stuck (anyway I could still hear the fan). I used a smaller piece of paper, so maybe yours was too heavy if the fan slowed down. But, has anyone noticed the sensor fan running at different speeds?
MB-BOB:
I also did this at lunch time. I knew if anyone checked it, it would be you! After I had parked the car for about 30 minutes at my house, I checked the overhead sensor fan again with the small piece of paper before I started up. The paper still stuck (anyway I could still hear the fan). I used a smaller piece of paper, so maybe yours was too heavy if the fan slowed down. But, has anyone noticed the sensor fan running at different speeds?
Last edited by MarkL; Jan 8, 2002 at 02:33 PM.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
Originally posted by benzomonterey
what an interesting can of worms I opened. I feel better at least knowing my original climate control thoughts were correct. I seem to have hypersensitive ears when it comes to my cars so it may just be the normal noise I am hearing.
what an interesting can of worms I opened. I feel better at least knowing my original climate control thoughts were correct. I seem to have hypersensitive ears when it comes to my cars so it may just be the normal noise I am hearing.
Admin Alumni
Joined: Nov 2001
Posts: 8,143
Likes: 19
See Garage
Originally posted by benzomonterey
the song is called Just Like Heaven by the cureThe Cure
the song is called Just Like Heaven by the cureThe Cure
Out Of Control!!
Joined: Nov 2001
Posts: 10,067
Likes: 11
From: Westwood, NJ
2004 Civic Si. FWD for the Win!
Yes, it's a great album!
It's on Kiss Me, Kiss Me, Kiss Me. Awesome album (double album). F**ked up videos, of course. Second-best album after The Head on the Door.
Saw them on that tour. Lots of freaks there.
MB-BOB, good call (though I properly identified the song earlier in another thread, to pat my own back). :p
Saw them on that tour. Lots of freaks there.
MB-BOB, good call (though I properly identified the song earlier in another thread, to pat my own back). :p
Junior Member
Joined: Jan 2002
Posts: 24
Likes: 0
From: Alabama
2024 EQE Sedan (on order)
switching noise, maybe
I heard that same humming noise from the overhead console on my C240, and finally convinced myself it's from the interior light dimming circuit. Just an opinion, but it sounds so much like a noisy little transformer to me.
I'd love to have someone tell me what it really is, though, and the confirming diagnostic
Jerry
I'd love to have someone tell me what it really is, though, and the confirming diagnostic
Jerry
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,230
Likes: 0
From: Gaithersburg, MD
2002 C240 6-spd (ret)
Jerry, the dimming of the light does make a noise like a transformer, but only while the dimming is happening. It took me a while to figure that one out too. But, if you've read the complete thread, I think we've concluded that there is a very small fan behind the temperature sensor slots near the SOS switch on the overhead console. A couple of us followed Richard's advice about the small piece of paper being held there by the fan's suction, and now that I've listened more closely, the slight sound is coming from that vent. I also tried the paper test after the car was off for several hours, and the suction was still present, as was the slight noise.
Look for Richard's post to this thread on the previous page and my follow-up and that of MB-BOB.
Look for Richard's post to this thread on the previous page and my follow-up and that of MB-BOB.
Last edited by MarkL; Jan 8, 2002 at 10:27 PM.
