That's great, sounds like there are two different high pitched noises coming from these cars, probably why it has been confusing to isolate. The one from under the engine cover is minimal compared to the discription of the bad ECU.

John

I'm not so sure that the problem is 100% truely solved. It may be that like in my car the noise is a little softer at times and then occasionally gets a little more noticable. If changing the ECM didn't totally resolve the problem it could be something else making the noise. Or all the ECM's are going to make the whine, some just more than others. Replacing could be a gamble, where you'll get a quieter one or maybe even louder.

With that said, I took some time today to try and trace it and it seems to be coming from the back of the car, not under the glove box where the ECM is. With my head under there and with the glove box out it's silent under there. I wonder if it isn't the fuel pump since I've heard a few of those whine over the years. They usually sound a little more mechanical and this noise is more sine wave-ish as someone else here said. If it is electronics related, are there any other electrical components in the back that could be making the noise? And maybe there are two noises happening here, and that's just really sad. I'm going in for service Friday and mentioned that I want them to look into it, though if we don't have answers here, they probably won't either, lol.

If you definitely have a high pitched noise coming from the rear, then there are THREE noises here, as the one coming from under the engine cover has been heard and confirmed by a variety of members, as well as G37 owners.

John

I'm so laughing, though I shouldn't be. What a whiny little Z. Do we know what is making this whine from under the engine cover? :eek:

No one actually has said definitively what it is. I can only hear it when I turn the car off, it continues to do it for a few seconds then dies off. It actually doesn't bother me, as you can't hear it when the cars running. The other two described sounds apparantly can be heard over engine and road noise, according to the members with the problem.

John

I'm still in Australia but I return Tuesday, I'll be taking my car in then. Thanks for the report back!

Agreed, its the fuel pump.

Has anyone heard of a clicking sound after they turn off the engine? I'm sure it's normal but just wondering what is that sound coming from the front right of the car from the driver's POV. I know it's something turning off, but can't figure what it is?

It's the fuel pump

Fuel pump. Man, don't we all understand that we don't have much sound insulation to save weight? A ton of cars would sound like this if they were doing this same technique. I love my Z and all the mechanical sounds it makes. I love that Nissan took the approach of, "You know, we will make this a purist's car. I makes some noise, but gives them the bang for the buck." God, I love this car. I guess you could say the lack of sound insulation keeps the price down. My '09 FX makes all the same sounds outside, but insulation keeps it out of the inside. Anyone looking at one of these cars shouldn't be worried. It's not loud. You just get used to it and don't even hear it after time.

At least I can hear when something goes wrong!

Okay, I'm sorry to bring this up again, but I'm finally getting the issue that others have reported with the "dog whistle" noise. As you can see, I know what the fuel pump sounds like. This "dog whistle" definitely is NOT it. I now see what people are complaining about. It's really loud! I didn't notice it for my first 10,000 miles, but now it's coming in loud and clear. It starts off intermittently, then becomes constant after about two minutes of driving. Has anyone heard of a new TSB or something official? I just don't feel like replacing what is guessed to be the ECU if I'd just get another screamer. Jesus is that loud. I take back my fuel pump comments. Again, sorry to bring this up, and I did do a search on this. The radio doesn't even cover it up. You especially can tell the difference as you move your ear around. (Ultra high frenquencies can be highly focused.) Thanks, and good luck with this. I now get it. I feel "not so nice" by saying it was the fuel pump.

Yep, when it's in gear the noise is constant. The younger the passenger the louder it seems to them. Young ears are more receptive to high frequency sounds. I keep adding bolt on mods, and it's not so noticeable. F.I. H.F.C.'s next, and hopefully that'll be the end of it.

I took it to the dealer today for the noise. You'll love this Ztoon... The older service manager couldn't hear it, and the younger heard it loud and clear. It's now really loud. Someone posted that the G37's are having this same problem and right now, Infiniti's solution to it is wrapping the ECU in sound insulating material without too much as to not overheat it. (Not the greatest results from this trick I have learned.)

I chose to have nothing done, but my dealer is reporting it and waiting for the next step. They said that it was really annoying as well. We'll see what happens, but just had to give a quick update. You'd better have some young or good ears. If you do, you get out of the car and your ears keep ringing. It really is that loud. We even turned up the radio and could still hear it loud and clear. Interesting, huh? That's a dealer that clearly heard it. I even disconnected my nav, unplugged any charger or adapter, turned off the radio, turned on and off the AC, shut off the fan motor, and it was still ringing in for my "younger" service manager to hear. He said, "yeah, that sucks!" It's not the fuel pump or radio. ECU. We'll see what happens. The G37 guys have a year jump on us.

I had a high pitch noise from the passenger side too. Drove me crazy until I realized that it was air squeezing thru the slits of a closed air vent.

------------------------BULLETIN JUST POSTED----------------------
ALL 370Z & G37 ECUs being replaced if you bring them in.
Problem Solved: Elmination of the high pitch frequency noise coming from ECU and hurting peoples' ears.:icon18: