Buzzing sound coming from speakers when radio on or off?!?! HELP!?
 

I have a 2008 C6 Coupe with Navigation and recently it has randomly started to make a whining/buzzing noise that gets louder the higher the RPM of the engine? I have tried to turn the radio off, turn the volume down, and change the source without anything working. It is very loud and noticable while sitting still or driving. I have noticed that some of time if I go over a bump it stops for a little bit. Eventually after a few annoying minutes it will go away. I haven't taken it to the local chevy dealership even though it is under warranty because it is an intermittent problem that I can not recreate. Has anyone ever had this sort of problem?

Check to see if you're hearing the small fan that pulls in cabin air to monitor temperature for climate control. It's to the right of the steering wheel down low just to left of climate/radio controls. If so, it can be changed easily and not very expensive. I've seen posts here where the owner just disconnected it. Maybe try a search for how to.

A lot of times when you start picking up rpm whine like that, you have a ground problem. I would think that if it was the Fan it would have a whine that would change pitch with the fan motor speed rather rpm's, but I'm no expert...

The whining is definetly coming from the rear speakers. When I start to hear it I try to pull over as soon as I find a safe place so that I can closer identify it but it always stops after a few minutes at the most. It is very loud and it definetly is affected by RPM even when I down shift it gets louder. This is really confusing me. If I could replicate the problem I think it would be much easier to diagnos but so far I have been unable to replicate it.

I have a 2008 without nav but I have had a similar experience on day while it was raining. There seemed to be a buzzing noise coming from the speakers. It continued after I turned off the car until I opened my door. I have not noticed it again but I can relate to your problem.

Sorry, you didn't say rear speakers in your original question. I don't have anything for that.

Update - I just spoke with one of my local REPUTABLE Chevy dealers and the service manager said he is almost positive he knows what my problem is and I will be taking it in next week to get it looked at. Once they take a look at it and if they fix it I will let all of you know incase you encounter the same problem or are already are. Check back.

My 2008 coupe is doing the exact same "buzzing" thing, but i believe it is coming through all the speakers. Any update on what the cause was for your vette?

Just read another thread by you. No IPOD in mine. I think it's the ground or ignition wires in my vette. Thanks anyway.

2008 vert same issue
 

Replaced both speakers in passenger door and whine still comes and goes as you hit bumps. Has gotten to the point that I don't drive car much. Any ideas.

I have the same issue with the speakers in my 06 but of course it won't do it when the dealership is driving it... have you had any luck finding out what the issue is? Seems to only do it with the XM - it whines and the bass sound goes in and out... I thought ground issue on the whine and loose connection on the other but Dealer thinks different... help

You guys sure it is not the front windsheield cowl panel, it buzzes at higher speeds but I do not think it increases with rpm.

Changing with rpm through speakers is an electrical problem, grounding maybe.

Let us know the outcome.

not possible
 

Stops when you turn radio off. Think it's time to trade for a porsche. No one seems to have an answer.

Keep the radio off and put in a CD.

My radio is rarely on.

Frustrating problem indeed.

Doesn't matter
 

Does it with CD, iPod, AM or FM.

Whine in Rear speaker
 

Did you ever get an answer for your problem?
I have the exact same problem except it doesn't go away and I think it is getting worse? The local Chevy dealer said it was not a ground and said these 2 inline noise filters between the radio and Power amp and the speakers should do the trick. They didn't (but at least they didn't charge me any labor but I am out the parts). They now insist it is a diode in the $600+ alternator. But I realized that the whine continues after turning off the engine until I open the door so it cannot be the alternator.

Sounds like poor shielding on the spark plug wires. If all else fails, try some new (not OEM) wires.

Carpe Diem thanks.
I was really looking for Epic_C6 as he said a Chevy dealer THOUGHT they knew what the problem was and Epic-C6 never posted THE answer or even the idea? The spark plugs/wires, alternator, line filters, ground, & PA gone bad (last 2 could still be it) were all ideas from different sources. Since the whine continues with radio AND ignition off (& door not yet opened) it has to be something still running on battery power? Doubt it could be spark wires or alternator. It could certainly be an expensive and lengthy troubleshooting. The local stereo guy wouldn't touch the OEM problems, but recommended the only place that may, Jimmy’s Car Stereo in Montgomery, AL 90 miles away.

You need to disconnect some things from the circuit. Do that by pulling connectors or pulling fuses so certain things aren't powered.

Disconnect the alternator from the electrical circuitry and take a short drive on the battery to see what happens. Make sure you insulate all exposed connector pins so you don't accidentally get a short from the battery to some ground. If you still get the noise then you know the alternator probably isn't doing it although to be absolutey sure you should keep the alternator from spinning as it could generate a spurious electrical field that is getting picked up in the wiring.

If you still get the noise pull the fuse to the HVAC so the fan doesn't come on.

Try pulling the fuse to the radio and see what happens. If you still get the noise something is being coupled into the wires going to the speakers and the radio isn't at fault.

I am not suggesting fixes only things that can be done to try and isolate the problem.

Bill

Thanks Bill, I have read, as you mention, you must be very careful running on battery only, and I am a car driver not the mechanic. I was really hoping a GM certified Mechanic at the local dealer would do something like this, but it certainly doesn't sem like it. Good suggestions.

The answer to my problem, finally got Justin from AAA Sound & Security in Dothan, AL to troubleshoot the problem. The Chevy dealer in Enterprise was wrong with trying to sell me a new $900+ alternator, but I knew that.
From Justin at AAA, "We diagnosed and fixed the OEM Bose amplifier. Amazing what a little piece of flux can do to compromise your audio system." 2 hours of labor.
Said it probably was that way from the beginning, so a mfg issue?