Mysterious electronic noise in engine bay

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kevink
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Mysterious electronic noise in engine bay

Post by kevink »

Okay, I finally got this on video. My car makes this weird electronic noise in the engine bay about one or two days per year. On those days, it will do it several times. It sounds like it's coming from the passenger side and it always happens when the key is not in the ignition. It may happen when the car is running, but I would never be able to hear it over the exhaust, so I'm not really sure about that. Any ideas? Fast forward to 0:38 for the noise.

https://youtu.be/Fk0H0f1zpbA
2011 9C3: 11.48 @118.
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kevink
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Re: Mysterious electronic noise in engine bay

Post by kevink »

Nobody has any clue what this can be?
2011 9C3: 11.48 @118.
lastcall190
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Re: Mysterious electronic noise in engine bay

Post by lastcall190 »

WTF O.o

My wife's Mazda makes some noises like relays clicking right when I shut it down. But this is a new one and I'm genuinely interested.

-J
2012 Caprice
2008 CVPI

Both gone but not forgotten...
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kevink
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Re: Mysterious electronic noise in engine bay

Post by kevink »

Weird, right? If it did it more than a few times a year, I'm sure I could figure it out, but it's so random.
2011 9C3: 11.48 @118.
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Mooseman
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Re: Mysterious electronic noise in engine bay

Post by Mooseman »

Maybe some left behind piece of police equipment that's dying?
2011 Caprice PPV, former RCMP test vehicle, never put into service
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kevink
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Re: Mysterious electronic noise in engine bay

Post by kevink »

It was civilian owned its entire life. There was never one bit of police gear installed in it.
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Pursuit
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Re: Mysterious electronic noise in engine bay

Post by Pursuit »

Just guessing here... EVAP purge Solenoid?...

Maurice
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cerbomark
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Re: Mysterious electronic noise in engine bay

Post by cerbomark »

Fuel tank pressure vapor system??
If that s it then it s normal. Sometimes I ll hear one of my cars doing that in the quiet garage. Like you said, one or twice a year that I ll catch it. I m sure it does it more often. One of those EPA things to stop fuel vapors from escaping into the atmosphere . Usually it come from closer to the tank but who knows how the sound it traveling.
2016 C1
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kevink
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Re: Mysterious electronic noise in engine bay

Post by kevink »

Yeah, I think that's what Maurice was getting at. It makes sense, since I think the EVAP solenoid is on the front of the pass side cylinder head and it's almost the only thing on that side of the engine with the exception of the fuse/relay box and the starter. Does anyone know how much voltage the solenoid gets? I think this is it:

https://www.gmpartsdirect.com/oem-parts ... cm9sZXQ%3D
2011 9C3: 11.48 @118.
Badnacho
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Re: Mysterious electronic noise in engine bay

Post by Badnacho »

That is definitely an odd one. Could be the CAN shutting down or something on the CAN powering down. Depending on the car the CAN may stay awake for up to 30 min. Most cars just click though, this is def out there. If it was more common you could do a current draw test and trace it.
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