2009 Elantra - High pitched SQUEAL from speakers

Hi Car Talk Community!

For the last 6 weeks I have debating calling in concerning this issue, but I haven’t been able to pull the trigger and do it.



Any help would be much appreciated.

Here is my problem:



On long road trips a high pitched squeal starts coming out of the speakers after about 3 hours of driving. If I turn off the radio it gets a little softer, but it’s still there. Leaving the car off overnight seems to fix it. I never notice it during normal driving. Just on long car trips.



My car has a CD player, aux input, USB input, and AM/FM radio.

I have an MP3 player plugged in to the USB input. Removing it doesn’t remove the squal.





Thanks so much!

Maybe I will have to call in!
Nobody I have spoken with has any idea what it could be… even my local service department.

Wish me luck!

If turning off the stereo doesn’t make the sound go away, it isn’t coming from the speakers.

The way you describe it sounds like feedback…but if it’s still there when the radio is off that wouldn’t make sense.

The only reason I think it relates to the radio is because the loudness of the squeal decreases when I turn the radio/mp3/cd off.

When I turn the radio back on it increases again to make sure it’s driving me crazy.

I find it odd that this issue only occurs after 3 straight hours of driving.

It appears your Elantra may have a separate power amp for the speakers i.e. there is an audio head and a separate power amp. If you could find a fuse for the amplifier, you could pull the fuse and see if that silences the squeal. A little research shows a 25 amp fuse to an AMP that is connected to ‘Hot at All Times’. So the audio head must put the amp to sleep when the off button is pushed.

Does the squeal change in pitch with the engine speed or the vehicle speed? You might have someone check for any alternating current voltage on the battery feed to that circuit.

Interesting problem. Let us know how it comes out.

A little late to the conversation, but my 2009 Hyundai Elantra is doing the same thing. Did you ever figure out what the issue was/how to solve it?

There’s radio interference suppression capacitors either on the alternator or the radio whose purpose is to prevent this kind of problem @abbyff6 . After years of use the insides can dry out and stop doing their interference suppression job. Ask you shop to check those are working. Check the radio/speaker grounding & shielding too.

I get a high pitched squeal though low volume, like a whistle in the background, from the am radio when I apply the brakes, and as I am stopped the pitch lowers the longer I am stopped. Audio available by request, but at the live with it for now.

I had a high pitch sound coming from the speaker and when I turned off the radio it became quieter. After some trouble shooting realized the sound was coming directly from the radio and more specifically the XM receiver inside the radio. I disconnected the the flex cable within the radio to the XM receiver and the sound went away. I don’t use XM, so this worked for me. Hope this helps someone in the future.

Hey tdscott,

I can’t tell you how much I appreciate your response.
I’ve been living with this on long drives for 9 years.

Can you give me a guide on how to access the flex cable I need to unplug?
I’m pretty call illiterate so any help is greatly appreciated.

Thanks again!