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Old 03-25-2010, 01:45 AM   #37 (permalink)
Phimosis
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Join Date: May 2009
Location: Oildale, CA
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Drives: 2013 911 4S
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Quoted from multiple:

"Replacing the ECU does not stop the noise. I am not a techie so excuse my lack of knowledge but the tech tried to explain it to me that if there was a mishap in the wiring into the ECU it could cause the whine, almost like it was a power surge."

"Are you saying, that they are saying, that it is the design of the wiring system causing the ECU to emit the noise?"

"Also according to the paperwork I got from Nissan that I forwarded to my attorney he said Nissan clearly stats there is a problem and that they are aware of it but they do not know how to fix it. "

"This is something interesting I've noticed about the high-pitched noise.... It starts out pretty much silent if your car has sat overnight and is cold. You'll notice, once you pull out of your driveway, it "rings" (like after you've been at a loud concert ear-ringing) when you press the accelerator lightly... Only at a certain position. Once the car warms up after about 2 minutes, it does it constantly. Mine has been taken to a dealer and we're waiting for the next step. "
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Putting all the above info together, I have an idea:

Solution: Embed the wiring block in rubber and put a rubber block around the wiring every foot or so. Also, may need to build a rubber case around ECU itself.

Rationale: Aternating current in a wire will 1) emit radio frequency and 2) set up it's own magnetic field. This is how electromagnets work on cranes in wrecking yards that pick up the junk cars. Also, ignore the part about emitting radio waves. I'm not saying it has anything to do with your car radio. From a physics standpoint, they will emit EMF (electromagnetic frequency). If each wire in the block is turned into an electromagnet with it's + and - poles alternating many cycles per second based in inputs and outputs from various sensors in the car, it would cause the wires to vibrate back and forth like guitar strings, making multiple, faint, tones in the audible range. Building a rubber block around the moving parts would significantly dampen the sound they emit.

supporting evidence: 1) MRI scanners have the same phenominon. If you've been in one, the "pop, pop, pop" or the "nnng, nnng, nnng" sounds are from wires in the send coils. They run about 5kw energy through a set of coils of wire that serve as an antenna to make RF. The RF is around 94mhz, which is too high to hear as a tone, but the current is pulsed on and off, so you repeately hear the wires move, hence the 'popping'. To keep the noise down, they embed the coils in a plastic table that you lie on. Between your weight and the damping characteristics of the plastic table, it makes the noise livable. 2) The noise gets worse as the car heats up. When a metal heats, its eletrical impedance rises. If sensors and send units rely on electrical impulses, the amplitude (voltage) of those signals hase to increase to compensate for the higher resistance in the wire. The higher voltage leads to a stronger magnetic field, which would lead to more wire movement and more noise.

Anyways, it's just a theory. I'm too busy with my work life to test it, so I'll just have to keep dealing wath the constant annoyance. I wrote to Nissan. Let's see if they reply...
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