speakers hum whistle

jigfeett

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Make
Chevrolet
Model
Tahoe LTZ
Year
2008
Miles
205124
Engine
5.3
radio has a hum whistle sound that changes pitch with throttle activation but sometimes it is not there at all.
Might be an alternator noise but not sure what is causing the issue.
I added a extra ground to engine block as a test but did not fix the issue.
Engine has a slight miss but there are no codes in any system.
Next step is a regular tune up plugs, wires, maybe check out coils.
Installed a crux BTGM33 bluetooth device which is completely plug N play no splices at all.
I thought that might be it but I removed it for testing and problem remains.

Are there any noise suppressors that actually work?
Radio noise suppressor or full electrical system that connects to the alternator wires?
I do see some on amazon etc. but reviews are sketchy
Any thoughts on this are appreciated.
vehicle has navigation and bose system
 

billr

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Did this just start; is this vehicle new to you? Generally, I would prefer to fix the root problem rather than just scab-on some kind of "filter" that wasn't needed with the OEM design.

Is it a stock (OEM) radio?
 

Mobile Dan

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Did you try to disable the Alt? Disconnect wire, wires, maybe fuse or belt....whatever is easiest.
 

jigfeett

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Hi, thanks
problem has been intermittent but seems to have been getting worse
We have had the car for a year
Radio is stock BOSE system and navigation
I thought that the crux BTGM33 bluetooth device which is completely plug N play no splices at all. That I installed was the issue but apparently not.
Dan,
I have not tried to disconnect the ALT, I will try by removing the belt, looks to be the easy way.
I will update later this week.
Thanks
 

jigfeett

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Billr, I agree to fix the issue rather than scab some filter on.
 

jigfeett

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I removed the crux Bluetooth device and the wife will let me know if the hum sound went away, I ran the car and drove it but did not hear anything but she will definitely let me know.
I will update asap.
 

jigfeett

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Today she said she did not hear the noise but I will let her drive it for a week before reinstalling it.
 

nickb2

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There was a gm issue with this back in the day, something with relocating the alt wiring harness, but that was for random misfires AND radio rum dum hum.

But if memory serves right it was for savana and express vans with a 5.3l

Theory was the wiring harness passed to close to the alt, creates a radio interference.

Probably, a tahoe has a different wiring path than a savana, so maybe blowing smoke out my arse, and yeah, removing the bluetooth thingy would have been my first go to also. Good call.
 

nickb2

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There are also fm bluetooth filters, but I have heard they rarely work. Usually, a newer upgraded bluetooth device work best.

This is after all a 2008. Alot of things have evolved since then.

Some will say it is distortion rather than a hum. It is hard to say if I or others cannot hear it, but since it has gone away since you discontinued the bluetooth and all back to normal, probably best to just get her a better install.
 

jigfeett

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Yesterday she said it still made some noise so I will be checking the items you listed. Also I noticed the Alternator wire is routed over the coils and not even secured away from anything just laying there
It goes down the passenger side of valve covers and coils then over to the Alt.
Thanks again
 

billr

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Wires that may be either transmitting or receiving electrical noise can be shielded by wrapping in aluminum foil and connecting the foil to ground (one place for the ground, anywhere along the foil). Make sure the foil completely covers the wires/harness in question
 

nickb2

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It goes down the passenger side of valve covers and coils then over to the Alt.
Yes, this is what I was alluding to this morning I think.

But I just cant remember if if it was for all 5.3l of this era or just for the vans.

Post #8 of this morning.

So maybe, if the harness is not shielded, may help to try to relocate or shield it.

What is electromagnetic shielding you may ask.

I merely write this here for others who may come on this thread.



So if speakers are humming or even worse, whistling, that is inherent to an overshoot or ringing very consistent with Bluetooth or other such devices working at a much higher clock frequenciy.

Since I know my engish is not on par with all you guys, I had this in one of my marque pages for futur reference, and here is the time to use it. I really how the article was written, it helped me understand more the effects of EMI.

Here is a link to that article I read back in 2010.

Close to around when your tahoe was built and GM had put out a few bullitins on this. Probably spelt that wrong also, TSB I mean.

 
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