Mircophones in roof of Denali making a Humming noise

[wade]

I have a 2003 Denali. Ever since I had it, at a stand still with the radio off, in the silence of the running truck, you can hear a faint 'humming' sound being emitted from both front & rear little circular microphones I believe they are in the ceiling of the truck.

Any idea on how to fix that? Its annoying at traffic lights, etc when it can be heard.

 

[Jamison]

They're not microphones, they're small fans that have something to do with the climate control system.

 

[tast101]

it's a little fan with a sensor thats tied to the Climate control. Just like a computer fan gets dirty and makes noise, these can too, so just get a can of air and blow it to seee if it cleans it out.

 

[BlizzardX23]

...fans? no...lol


Hes talking about the microphones in the ceiling for onstar...Its directly above the driver seat...Mine does the same thing Wade...if this is what your talking about...

but I have an aftermarket navigation though

 

[tast101]

I'm taking pics tomorrow, because I don't have onstar and I have the lil fan above the driverside left ear.

 

[BlizzardX23]

I took my microphone out already when I took my headliner out Thats how I know it was a microphone for our OnStar

 

[NathanJax]

...fans? no...lol

Hes talking about the microphones in the ceiling for OnStar...Its directly above the driver seat...Mine does the same thing Wade...if this is what your talking about...

but I have an aftermarket navigation though. I took my microphone out already when I took my headliner out That's how I know it was a microphone for our OnStar

The OnStar microphone is what your talking about. Black 1/2 inch by 1 inch piece that clips on the upper center counsole that has the map lights in it. I think the piece he is talking about is the small plastic grill, about the size of a silver dollar that sits directly above the drivers left ear...




Here is the GM bulletin regarding it...

Document ID# 1639237

Subject: Buzz Noise From Headliner Above Driver - keywords ac air aspirator cover fan grille HVAC interior microphone sensor speaker temperature vent vibration #PIT3511 - (03/29/2005)



Models: 2000-05 Cadillac Escalade

2002-05 Chevrolet Avalanche

2000-05 Chevrolet Silverado, Suburban, Tahoe

2000-05 GMC Sierra, Yukon, Yukon XL, Yukon Denali

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Condition/Concern:
Dealer or customer may comment that they have a buzz or vibration noise emanating from the headliner in an area that looks like microphone or a speaker.

Recommendation/Instructions:
The plastic escutcheon grill, which is round and about the size of a half dollar and located just above the driver to the left, is the interior ambient temperature sensor. The sensor is used in conjunction with the automatic HVAC (C68). On occasions, this sensor has been known to make a buzz or rattle sound. The sensor uses a small fan to pull air over the sensor. This buzz noise may be intermittent.

Although it may not be possible to alleviate all of the buzz or noise from this sensor, Engineering has found that if the sensor is installed incorrectly that it may bind and cause the fan to make a buzz noise. Remove the sensor and while doing so check for any binding. Reinstall the sensor and re-test. If the noise is still present, the sensor itself may be noisy and require replacement.

 

[BlizzardX23]

wow...I stand corrected...You guys were right, I was wrong.. I would have honestly bet my life it was a microphone when I unplugged it...I would have just died....oh well, you guys are smarter then I am..thats ok...Now I know why mine hums ...very annoying

 

[YNOT]

big brother...lol

 

[Maverick7687]

I have a 2003 and mine does the same thing. I did a little researching on it and found that service bulletin though so I wasn't that worried about it. How do those come out? Do they have little clips that pop out or does that side of the headliner have to be removed?

 

[wade]

thanks Jax

 

[yooformula]

damm, I was wondering about the same annoying sound but never got around to messing with it. Anyone know how it comes out?

took care of it this afternoon. snaped the cover off, sprayed it out with compressed air then snapped it back in, very easy.

 

[zdude]

To remove/replace this aspirator (I did it a few times), the easierst way is this:
1. Use a wide trim tool, kind of like a wide flat, slightly angled crow bar.
2. Work around the grill/bezel little by little and work it off. It's held on by those little burr shapes things, I think 3 or 4 of them.
3. With drivers door open, pull the rubber seal away from about the A-pillar to the B-pillar. Slide your hand in there and grab that sucker and work it out. There was enough slack in the harness for me to get it all the way out with it connected. Be careful not to bend the headliner too much, as it might crease and look nasty forever.
4. Clean or replace, and then slide it back in and hold in place while pushing the grill snaps back into it.
5. Put the rubber seal back in all the way, and your done.

I tried cleaning mine, but it didn't really help much. It was still noisy. So I ordered the Dorman part and changed it, but the Dorman was actually noiser than the bad GM part. I returned it for a GM replacement part which is much quieter.
I've seen some say you have to remove the sun visor and some plastic trim, but I didn't.

With the assembly hanging out of the headliner, you can leave it plugged in and see if it is really noisy or if it just some vibration with noise of hitting or rubbing against the sheetmetal roof or something. Mine was definitely just a noisy part. Testing like this, the Dorman was loud, but the GM part couldn't be heard unless you put your ear next to it, and then it was only a faint 'wirring' sound.

 

[tahoe7689]

so mine was doing the same thing, so I thougt it was onstar, so I just took it out because I dont subscribe to onstar. My ac/heater is messed up (all hot or all cold) do you think removing this fan thing could be causing the problem with my ac/heater?

 

[BOSS]

Jesus christ,,,,,,I wuld bet my life that was a mic...I took mine out, thak god i didnt toss it....

B

 

[jdpromo33]

Jesus christ,,,,,,I wuld bet my life that was a mic...I took mine out, thak god i didnt toss it....

B

Yes this is called an Apirator and I too took mine out when it started making a noise. Then it started to get really hot in the cabin. Took it to the mechanic who replaced the Apirator for $45 and all is good now.

EVERYONE (including me) thought this was a Onstar microphone LOL!

 

[BOSS]

Yes this is called an Apirator and I too took mine out when it started making a noise. Then it started to get really hot in the cabin. Took it to the mechanic who replaced the Apirator for $45 and all is good now.

EVERYONE (including me) thought this was a Onstar microphone LOL!

I officialy feel like a dumbass....thankfully I wasn't advising people on it that I can remember anyway

B

 

[01yukonslt]

hahaha i woulda never guessed that... i told my girlfriend it was the onstar mic and she better watch what she says because big brother is listening.

 

[JeepGuy]

I just picked up my new to me 2005 Tahoe this morning and discovered the rear one on mine was buzzing. Merely blowing out the built up dust didnt fix mine. They ARE serviceable for anyone handy enough or inclined to give it 20 minutes of your time. The hardest part was coming to the eventual conclusion that the only way to get them out is through the hole itself. I thought wrongly that there would be a way in through either a some light or the vents.

For anyone interested here's what I did.
1. I took my ghetto fabbed trim tool (aka bent butter knife) and pried off the plastic cover.
2. Widen the opening by carefully cut the headliner about a quarter inch in four places equally around the opening.
3. Pull the aspirator and wiring through the opening with some plyers...two pairs and some wiggling got mine out fairly easily.
4. Unsnapped the wiring connector.
5. Carefully separate the top and bottom "housing" to the aspirator.
6. Separate the fan and electrical board from the bottom piece...there's a couple black pieces that just took a light push to release it.
7. Carefully bdnd back the thermometer to allow the fan to slide off.
8. Using some compressed air blow off all the dust, I washed all the pieces besides the electrical board, and inspect for any damage. The mating surface on mine between the fan and the lower "rubber seat" was a bit rough causing a clicking. It took some gentle scraping but after a couple tries the clicking went away. You can test it by just pitting fan back in and hitting it with the air. A little petroleum jelly on the shaft...hehe...and she was good to go.
9. Reassemble.
10. Connect wires and jam it back in.
11. With a little wiggling around get the aspirator centered above the hole.
12. With even pressure snap the cover back on...the headliner should flex enough to allow counter pressure from the roof.

HTH

Darren

 

[03YukonNH]

I just picked up my new to me 2005 Tahoe this morning and discovered the rear one on mine was buzzing. Merely blowing out the built up dust didnt fix mine. They ARE serviceable for anyone handy enough or inclined to give it 20 minutes of your time. The hardest part was coming to the eventual conclusion that the only way to get them out is through the hole itself. I thought wrongly that there would be a way in through either a some light or the vents.

For anyone interested here's what I did.
1. I took my ghetto fabbed trim tool (aka bent butter knife) and pried off the plastic cover.
2. Widen the opening by carefully cut the headliner about a quarter inch in four places equally around the opening.
3. Pull the aspirator and wiring through the opening with some plyers...two pairs and some wiggling got mine out fairly easily.
4. Unsnapped the wiring connector.
5. Carefully separate the top and bottom "housing" to the aspirator.
6. Separate the fan and electrical board from the bottom piece...there's a couple black pieces that just took a light push to release it.
7. Carefully bdnd back the thermometer to allow the fan to slide off.
8. Using some compressed air blow off all the dust, I washed all the pieces besides the electrical board, and inspect for any damage. The mating surface on mine between the fan and the lower "rubber seat" was a bit rough causing a clicking. It took some gentle scraping but after a couple tries the clicking went away. You can test it by just pitting fan back in and hitting it with the air. A little petroleum jelly on the shaft...hehe...and she was good to go.
9. Reassemble.
10. Connect wires and jam it back in.
11. With a little wiggling around get the aspirator centered above the hole.
12. With even pressure snap the cover back on...the headliner should flex enough to allow counter pressure from the roof.

HTH

Darren

I did this exact same thing with my front climate control fan last night but now you are telling me there's a rear one too?! I thought I heard another noise coming from back there but I didn't think it was another fan thingy. I will have to take that one out and clean it and oil it. What a pain. I 've never seen such a thing before.