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2007 Outback 2.5i
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Discussion Starter #1
I have an 07 outback 2.5i non-turbo 5spd and It has an aftermarket head unit. said unit has been perfect until yesterday when I noticed a whining through the stereo that increased consistently in volume when rpm's go up. I have some theories but wanted to hear everyone else's thoughts before I embarrass myself lol.
 

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Outback 2011 3.6R Premium
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This is often caused by bad spark plug wires (or copper plug wires which are not typically used these days)

Seagrass
 

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Discussion Starter #3
This is often caused by bad spark plug wires (or copper plug wires which are not typically used these days)

Seagrass
Oh ok I hadn't even thought of those. Thanks, I'll check those out! Now electric stuff is where my knowledge is limited, which I'm sure is evident, but would the alternator have anything to do with that? I have noticed that it occasionally has a bit of trouble keeping up with the load sometimes, and my heat and ac have been very slow since the whining started. Maybe its just going out and somehow affecting those?
 

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Oh ok I hadn't even thought of those. Thanks, I'll check those out! Now electric stuff is where my knowledge is limited, which I'm sure is evident, but would the alternator have anything to do with that? I have noticed that it occasionally has a bit of trouble keeping up with the load sometimes, and my heat and ac have been very slow since the whining started. Maybe its just going out and somehow affecting those?
If your alternator is not functioning correctly this could also be the cause of the problem.The "regulator packs" in the alternator also contain the brushes and you can typically purchase a rebuild kit from Amazon like the following, (need to confirm which one fits your alternator)


Seagrass
 

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Discussion Starter #6
If your alternator is not functioning correctly this could also be the cause of the problem.The "regulator packs" in the alternator also contain the brushes and you can typically purchase a rebuild kit from Amazon like the following, (need to confirm which one fits your alternator)


Seagrass
Ok cool. thank you so much for all the help and replies! I will try a few of the suggestions and update ya with the solution!
 

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Discussion Starter #7
Do you have the original speakers? Clarion speakers will make this noise when they short out.

Bad grounds will create the whine. Check your battery cables while you're under the hood.
Yea they are stock speakers. I am planning on getting a few new speakers and a 10-inch sub for it too so hopefully that'll do it. The grounds could also be it too. I'll try a few things and update you guys on what seems to work. Thanks for all the help!
 

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Discussion Starter #8
UPDATE: I checked out the grounds and cables and such when I was installing my 20 inch LED and everything looks right. Next move is to replace spark plug wire pack (because it can't hurt to do that anyway) and then take out the speakers and see what's up with those, and last resort I'll get a new alternator.
 

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2005 Outback Wagon 3.0 L.L. Bean
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Plug wires unlikely. (They will have a ticking sound more than whining)
Speakers will not cause whine.
A bad diode in the alternator may be the cause, but would not be my first step in diagnosing. You would only be charging at 2/3ds power if that were the case.
It sounds like you are experiencing a ground loop. Check the radios chassis ground. If it is not good, it will hunt for a ground through the antenna or even the illumination. While the radio is playing, un-plug the antenna and see what happens. Ground to metal in the car, not another "ground" wire.
 

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Discussion Starter #10
Ok Ill give that a shot. I did the plug wires anyway just to see what happened. no difference lol. I did have it die on me though so thats new. Its new thing is to just start idling at 500 rpms for a couple seconds right after i stop accelerating. Thinking the alternator is the likely Culprit. It also has nearly cut out when i turn the steering a notch at idle.
 

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2020 Limited XT Magnetite Gray
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It sounds like you are experiencing a ground loop. Check the radios chassis ground. If it is not good, it will hunt for a ground through the antenna or even the illumination. While the radio is playing, un-plug the antenna and see what happens. Ground to metal in the car, not another "ground" wire.
This is where I would be looking, a bad ground.
 

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2016 Outback 3.6R Ltd. w. Eyesight
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Using non-resistor spark plugs can cause noise and interference with radio and phone transmission. But unless you happened to change plugs right before this occurred, that's not your issue.
 

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Discussion Starter #15
Using non-resistor spark plugs can cause noise and interference with radio and phone transmission. But unless you happened to change plugs right before this occurred, that's not your issue.
no I didnt do that. its now reallllly wanting to die on me whenever i let the clutch out in neutral right after some driving. It rumbles and everything and lights dim way low. does this with any power steering input whatsoever at idle
 

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You just described/confirmed your alternator failing. It was noisy before, now it's only been partially charging for the past week. Long enough to have affected the car battery. Your battery is primarily for starting your car. Once it's running, the alternator provides all the power. Your alternator is really 3 AC generators on a spindle, 1/3 out of phase, with 6 diodes rectifying AC to DC. If one diode fails then you lost 1/3 output. It may still run. Your car won't be happy. Worn bushings and brushes in the alternator may cause similar charging issues but the associated radio noise is characteristic of failed diode(s).
 

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Discussion Starter #17
You just described/confirmed your alternator failing. It was noisy before, now it's only been partially charging for the past week. Long enough to have affected the car battery. Your battery is primarily for starting your car. Once it's running, the alternator provides all the power. Your alternator is really 3 AC generators on a spindle, 1/3 out of phase, with 6 diodes rectifying AC to DC. If one diode fails then you lost 1/3 output. It may still run. Your car won't be happy. Worn bushings and brushes in the alternator may cause similar charging issues but the associated radio noise is characteristic of failed diode(s).
ok thats kinda what my inclination was. Thank you for the detailed and thorough explanation!
 

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You just described/confirmed your alternator failing. It was noisy before, now it's only been partially charging for the past week. Long enough to have affected the car battery. Your battery is primarily for starting your car. Once it's running, the alternator provides all the power. Your alternator is really 3 AC generators on a spindle, 1/3 out of phase, with 6 diodes rectifying AC to DC. If one diode fails then you lost 1/3 output. It may still run. Your car won't be happy. Worn bushings and brushes in the alternator may cause similar charging issues but the associated radio noise is characteristic of failed diode(s).
Not necessarily.

If the engine is misfiring on one or more cylinders at idle (lowering the idle rev’s of the motor) then the alternator would not be supplying a high enough output. This would result in lights dimming etc as described.

You may have more than one problem so take your time and troubleshoot the problem using the symptoms.

Seagrass
 

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Discussion Starter #19
Not necessarily.

If the engine is misfiring on one or more cylinders at idle (lowering the idle rev’s of the motor) then the alternator would not be supplying a high enough output. This would result in lights dimming etc as described.

You may have more than one problem so take your time and troubleshoot the problem using the symptoms.

Seagrass
Good point. now excuse my ignorance but a misfire would be noticeable right? like id feel a wobble in acceleration or some timing would sound off? especially since its a manual. i really dont know im just asking lol
 

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Good point. now excuse my ignorance but a misfire would be noticeable right? like id feel a wobble in acceleration or some timing would sound off? especially since its a manual. i really dont know im just asking lol
And you'd more than likely have a check engine light if that were the case.

Noise suppressors for car audio systems have been a thing for as long as I can remember.

Cheap chargers for cell phones that are connected to the stereo through a wired connection are the most likely to introduce noise. Are you getting tunes through your phone while charging by any chance?

@Tishers pls help
 
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