"Electrical" noise behind driver
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Joined: Nov 2005
Posts: 79
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From: Austin Texas
"Electrical" noise behind driver
I posted this question a while back and did not get any responses so I am going to try again.
I have a 98 coupe that for the most part is stock. If i drive the car on trip for more than an 1 - 1.5 hours it develops an electrical noise that seems to be comming from the driver side rear speaker. However it does not increase with the RPM's like alternator noise in the stereo and if I turn the radio completely off, the noise is still there.
If the car sits for while and cools off, the noise goes away, until the next trip.
It is very annoying and I hope someone recognizes this and can advised what it is and how I can eliminate it.
Thanks!!
I have a 98 coupe that for the most part is stock. If i drive the car on trip for more than an 1 - 1.5 hours it develops an electrical noise that seems to be comming from the driver side rear speaker. However it does not increase with the RPM's like alternator noise in the stereo and if I turn the radio completely off, the noise is still there.
If the car sits for while and cools off, the noise goes away, until the next trip.
It is very annoying and I hope someone recognizes this and can advised what it is and how I can eliminate it.
Thanks!!
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I seem to recall the early C5's had a noisy fuel pump not sure if this carried over to 98 but theres my .02
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From: Anthony TX
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If the noise is coming out of the SPEAKER it's self and not from the general area of the rear compartment, you could have a bad capacitor in your amp or are getting cross talk from some other source. If my memory services me correctly, you have an aftermarket stereo. system. If you have access to an O scope, you could check the speaker output for the noisy signal.
97 & 98 C5's had known noisy fuel pumps. They make a low pitched hum that varies with fuel pressure. There is a TSB on that very issue. The hum drove my wife crazy
and that was one of the very first warranty issues that I had repaired on my 98 coupe. I'm a 26 year submarine sailor and the noise never bothered me. What noise?? 
BC
97 & 98 C5's had known noisy fuel pumps. They make a low pitched hum that varies with fuel pressure. There is a TSB on that very issue. The hum drove my wife crazy
and that was one of the very first warranty issues that I had repaired on my 98 coupe. I'm a 26 year submarine sailor and the noise never bothered me. What noise?? BC
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Joined: Nov 2004
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From: Bartlett IL
I work at a Mercedes dealer (I know, not a C5) but the SL 55's have a problem with a electrical short noise. It does sound exactly like a high voltage electrical short. Its the fuel tank on those. The sound of the fuel pumping through one of the ports makes noise. So in short I would look at the fuel pump/ sender assembly. If you think its the speaker try unpluging it and see if it makes the noise again. But I bet its the fuel system.
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The first C5s used a fuel pump from another GM car. It was noisy but did not bother customers of the other car since the pump was some distance from their ears. In the Vette it is about 3 ft away and the noise is tiresome after a while. I had the fuel pump replaced on my 97 some time in late 98.
Bill
Bill
