Pontiac Vibe 2006 defrost vibration


#1

When the defrost button is on, my Vibe makes a continuous vibrating noise that stops if you hold your hand on the button constantly while driving. The defrost has to be constantly on as even in good weather, the windows fog up. The dealer wants upwards of $700 to get into the dash and explore. I’d settle for just getting rid of that noise. Any thoughts?


#2

See if you can find the exploded view diagram for your Vibe in the attached link. If not, stop by the local GM dealer and request of the guy at the parts window an “exploded view drawing drawing” that shows your defrost button installation. From there you can, if you’re at all mechanically inclined, do some disassembly and see if you can fix it yourself. I’d suggest some nylon interior panel tools (like little nylon crow bars) to prevent scarring the interior parts. The tools are cheap, typically about $10 for a package of four to six tools.
http://www.toyotapartsoverstock.com/

NOTE: I believe the button is in the console.


#3
The defrost has to be constantly on as even in good weather, the windows fog up.

Sounds like you might have heater core leak. Are you losing antifreeze?


#4

vicl wrote:
The defrost has to be constantly on as even in good weather, the windows fog up.

This doesn’t seem right to me. Adding to insightful’s question, do you ever notice a smell like maple syrup in the car?

Do you know if your air conditioner is working correctly?


#5

While unrelated to the resonance, I too think insightful may have a good point. And an excellent observation.


#6

You mean if you continue to press on the “defrost” button, the noise stops? hmmm … my first guess is a ventilation door actuator is failing. And by holding down that button you prevent the computer from electrically actuating the motor as long as the button is pushed. the computer sort of freezes up and doesn’t know what to until the button is released. This presumes of course your Vibe uses electrical actuator motors (often stepper motors) for that function. I’d guess a 2006, that would be likely.

My second theory is that holding the button only affect the sound b/c you are pressing on the dashboard. In other words if you experimented around, you could press other places and the noise would stop too. This theory is based on debris has entered the vents under the windows and gotten into the ventilation path, and that stuff is fluttering as the air flows past, and pressing on the dash somehow affects the sound it makes. It’s like one time I had a stereo speaker that would buzz on certain notes of the intro to Led Zeppelin’s “Stairway to Heaven”, but if I pressed on the edge of the speaker the buzzing would stop.