Short duration buzz noise in dash secs after vehicle start

[darrell]

I have a 2010 v6 w/tech package. Just seconds after start-up a low level
buzz noise for a short duration seems to be coming from the dash.
Vehicle has approx 20,000 miles. It's a new noise just started in last couple of days. Best I can determine all functions of the Tech package work as normal.
ANY IDEAS? Is this a sign the head unit is destined to fail?

Is there a servo motor somewhere in the dash unit?

Thanks,
Darrell

 

[Mark_888]

Is is coming from front center speaker?

 

[darrell]

Is is coming from front center speaker?

I don't think so!

Radio is off, it is a low level buzz lasting just a second or so. Happens within 5 or 10 seconds after vehicle start.

 

[tompass]

I had a buzz occasionally coming from the chrome trim surround on drivers side dash vent. Next time you start the car, place your finger on that trim and apply some pressure to see if it is the problem.

 

[mikec]

I haven't taken the time to dig out the factory service manuals but I'd be surprised if the heater/AC system doesn't have a motor controlling the water flow through the heater. Have you recently dialed in different temps on the HVAC control panel... just before the noise started? As a quick test, with the engine idling, dial the temps up/down with the fan on low and see if you can make the noise happen. Or think back to the temp & air duct settings you had prior to the noise and select those a minute or so before turning the car off... if the noise goes away on startup...

Not it? Then next time you start the car, put a hand on the lower lip of the DVD slot and hold it there until you hear the noise. If you can feel vibrations in sync with the noise it might be the head unit: the DVD/CD changer or the hard disk of the NAV system is getting goofy as it spins up. The hard disk can be replaced independently of the Tech package head unit (as can the DVD/CD unit) according to the factory service manuals. If that's the case... maybe you'll get a free NAV database update out of the repair when the hard drive is swapped!

mike c.

 

[darrell]

I haven't taken the time to dig out the factory service manuals but I'd be surprised if the heater/AC system doesn't have a motor controlling the water flow through the heater. Have you recently dialed in different temps on the HVAC control panel... just before the noise started? As a quick test, with the engine idling, dial the temps up/down with the fan on low and see if you can make the noise happen. Or think back to the temp & air duct settings you had prior to the noise and select those a minute or so before turning the car off... if the noise goes away on startup...

Not it? Then next time you start the car, put a hand on the lower lip of the DVD slot and hold it there until you hear the noise. If you can feel vibrations in sync with the noise it might be the head unit: the DVD/CD changer or the hard disk of the NAV system is getting goofy as it spins up. The hard disk can be replaced independently of the Tech package head unit (as can the DVD/CD unit) according to the factory service manuals. If that's the case... maybe you'll get a free NAV database update out of the repair when the hard drive is swapped!

mike c.

Mike, I think you may be on to a probable cause. It defiantly seems to be something mechanical and the Nav HD initial spin starting up or HAV controls could be the issue. The noise usually occurs approximately 17 seconds after engine start for a duration of maybe 2 seconds and has not happened again until next start. I have attempted to make sure I have everything turned off such as cooling/heating system, radio, DVD/cd etc.
On the other hand wouldn't the NAV HD spin without starting the vehicle and accessories switched on?
Noise only occurs seconds after engine start!

 

[darrell]

I haven't taken the time to dig out the factory service manuals but I'd be surprised if the heater/AC system doesn't have a motor controlling the water flow through the heater. Have you recently dialed in different temps on the HVAC control panel... just before the noise started? As a quick test, with the engine idling, dial the temps up/down with the fan on low and see if you can make the noise happen. Or think back to the temp & air duct settings you had prior to the noise and select those a minute or so before turning the car off... if the noise goes away on startup...

mike c.

LATEST UPDATE...........on short duration buzz sound approximately 17 seconds after engine start-up

Service dealer diagnosed issue as a defective actuator located in the dash.
Vehicle is presently at dealers with dash removed awaiting ordered part for replacement later this week.

 

[darrell]

LATEST UPDATE...........on short duration buzz sound approximately 17 seconds after engine start-up

Service dealer diagnosed issue as a defective actuator located in the dash.
Vehicle is presently at dealers with dash removed awaiting ordered part for replacement later this week.

Dealer replaced actuator that controled vent air flow.
Issue resolved!

 

[Tin]

did the buzzing start immediately after you start the engine or the buzzing start at 17 sec? mine would buzz when I first start the car, thought it was normal.

 

[ImInPA]

It could be the electronic ignition lock buzzing. Have the dealer check it out.

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[darrell]

did the buzzing start immediately after you start the engine or the buzzing start at 17 sec? mine would buzz when I first start the car, thought it was normal.

Tin, the short duration buzz is not normal.
Dealer replaced the actuator motor located under dash. The motor controls heating/cooling
air vent and is activated a few seconds after car start.

 

[darrell]

It could be the electronic ignition lock buzzing. Have the dealer check it out.

See post #8 issue resolved! it didn't take the dealer very long to determine the problem. It did take a few days for a replacement part order.

 

[Flamenguista]

Mine has the same issue. Just took it in today.