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Old 04-25-2019, 03:40 PM   #1
shifty
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SOLVED! Annoying noise - can't figure it out

Mystery solved! Unlikely answer is in post #7

Here's the deal, before you say anything, you should know things:

- My hot/cold blend door motor is operating fine and quietly.
- My recirc/fresh air door motor opens/closes quietly when I push its button.
- The recirc door motor is close to the sound source, so I unplugged its power to test, no change at all.

That said, got this annoying noise I can't figure out for the life of me.

- Happens most when I hit hard bumps, turn hard or take bumpy turns.
- Sounds like it's coming from behind the passenger airbag.
- It reminds me of a toy gear winding back/forth, or a zipper being zipped back/forth.
- There's also some rattle involved.

Any thoughts on what could be causing this? It's making me a little crazy.

I'm open to the idea it could be one of the motors, I know they break, plastic gears crack. But all the climate door motors seem to work well, quietly. I don't get heat all the time. Recirc button and door works great to change modes. Good replacements are expensive!
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Last edited by shifty; 05-08-2019 at 03:20 PM.
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Old 04-26-2019, 07:41 AM   #2
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Hmmmmm let's see

So if you add a mechanical event like bumps, the sound appears. It could be something that is moving becoming disrupted by the event like a motor as you stated. Or something that is not moving becoming disrupted by the event.

Assuming it's something moving like the blower motor, be sure it's off and test it with a bumpy road. If need be, pull fuses to turn things off that don't have it's own switch.

One other thing you can try is tapping on things with a rubber mallet. The only thing that really makes sense is the blower motor which is by the passenger air bag. You can easily tap on it. Our blower motors are the worst. Always noisy.

I have heard relays oscillate before. Just a thought. Unplug them and try the same event.
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Old 04-26-2019, 09:16 AM   #3
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Re: Hmmmmm let's see

Quote:
Originally Posted by speedygonzales View Post
The only thing that really makes sense is the blower motor which is by the passenger air bag. You can easily tap on it. Our blower motors are the worst. Always noisy.
My blower motor became more noisy lately, started making a light rhythmic ticking sound when the fan is on, almost like there's a leaf stuck above the hamster wheel (squirrel cage, whatever) and the fins are slapping it. Faint ticking increases with fan speed.

I pulled it recently to try and figure out why - couldn't find any leaves or anything coming in contact with the hamster wheel. Maybe the motor is going or the hamster wheel is out of balance.

But not sure that's the cause of the sounds, the mechanics of it don't match.

The sounds I'm hearing are never there if the engine is off or when the car is stationary. It's never heard when using HVAC controls. They're most noticeable in two cases:
1) I swerve suddenly at 25-35mph, that causes the "zipper" sound almost like this gear at 50s in this video or 1m03s mark in this video if the motor went back/forth, winding up and down
2) I jump on the gas and let off it abruptly, this causes one single click noise the moment I let off the accelerator, but it's coming from behind the glovebox, not the pedal. Almost as if a door is tapping shut.

Next time I'm out and about, I'll unplug the wire to the blower motor.

That zipper noise though, the reason I thought it was one of the door motors is because it sounds damn near exactly like what a motorized kids toy sounds like when it's turned off and you forcibly move the DC motorized parts back and forth.

I'll also try to get someone to drive and do these things while I have my hand on the recirc air door to see if that's what's clicking and also to get better audio, put my hands on the motors during those motions.
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Old 04-26-2019, 09:35 AM   #4
cashforclunkers
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Re: Annoying noise - can't figure it out

You don't have one of those noisy sandwich makers in the passenger seat do you? Lol
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Old 04-26-2019, 11:22 AM   #5
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Re: Annoying noise - can't figure it out

Quote:
Originally Posted by cashforclunkers View Post
You don't have one of those noisy sandwich makers in the passenger seat do you? Lol
Don't you dare talk about my wife like that!
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Old 04-26-2019, 10:02 PM   #6
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Re: Annoying noise - can't figure it out

I'm beginning to think a piece of dash broke off and slid over into the corner behind the airbag and that's what I'm hearing jamming up. I just can't seem to find a way to access behind the airbag without fear the thing will blow up in my face.
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Old 05-06-2019, 04:50 PM   #7
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Re: Annoying noise - can't figure it out

Problem solved! You'll never believe what it was.

I apparently stuck my billet flashlight in the sunglass holder for the overhead console a few weeks ago. It was milled, so it has ribs down the body.

Turn left, flashlight slides left across something plastic in there, zzzzzip *thunk*.
Turn right, flashlight slides back, zzzzzzzip.
Accelerate quickly, flashlight rolls forward, *thunk*.
Let off the pedal again, *thunk*.

It all makes sense now. So it wasn't one of the blend or recirc door motors. It was in the overhead console the whole time and it sounded - for whatever reason - like it was coming from the passenger's side glovebox.

Bizarre.
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