I have a enth 350z m/t. with 600 miles. When i come out of first i get this weird rattle noise, and when I am cruising in any gear, mostly 5th and 6th at about 70-80 mph, I get a very annoying whining noise. If I step on the throttle a little bit the noise goes away. When I have the throttle slightly depressed at cruising speed is when i hear the noise most. I can hold the trottle at that position to hear the noise, but if I let go or push down the noise goes away. Does anyone know what can cause this? Should I bring the car in or wait to see if it gets better or worse with more miles.

 

I have the same problem and it is F@cking annoying. I took it in once and they said it was normal b/c the gears were so tight. I have 6100 miles. Let me know if you get it fixed.

 

I am going to wait til my first service to bring it in and have them look at it. I'll keep you posted if the tell me any different. Did the CAI make the car noticably faster, What one is better the AEM or Injen CAI?

 

To be honest, I couldnt really feel a difference. It sounds good though. I havent been to the track since I installed it. That will be the best way to see if it helped. I chose Injen because I had seen some better dyno numbers. I have owned both in the past and they are both good.

 

I have the same noise. I hear it on a lot of cars though. Sort of like a wierd whistle when you let off the gas.

 

Do a search, as this topic was addressed quite a while ago, but the gist is that the fuel pump whines at 75-80 mph on everyone's Z. i.e. not a malfunction, just the way the car works.

 

I got the injen. Noticably faster? not so much, but it does feel more responsive, and it sounds great

 

It's not the frickin' fuel pump, it's the rear diff gears. Do a search for my posts on the subject to see all the reasons why.

Desmo

 

Desmo, I agree with you I originally thought it was coming from the diff. also. Did you get yours fixed? I am still hearing the noise, i have almost 1K miles. It is starting to do it more and more, now from speeds of 60 and up, only when i have very light pressure on the throttle, in 5th and 6th. The other day i wanted to do a top speed run on an open road, the noise got very loud (like a missle) when i got to a 140mph, it sounded like it was going to blow up or something. By the way my needle hit 160. It was whining like a son of a b!t@h. The car handles great at that speed, feels tight, and planted, I wouldn't hesitate to do it again!!
I have to get this noise fixed though, its driving me nuts during my commute.

 

I have the same problem and it's been pissing me off!!! I thought it was the fuel pump but I don't know. I am going to have the dealer check it out.

 

After my change to Redline tranny and differential oil, the whine is not as loud as before. I can barely tell its there now ever since I changed it. So I dont know if its the fuel pump or not, but all I know is that Redline did something about the noise. Never really bothered me much though...

 

I haven't noticed this sound at 60-80 but I did a WOT run on I-5 about a month ago. The car topped out at about 130 in 5th and when I accelerated more in 6th that was when I noticed the whine. It got worse as the mph climbed. It sounded kind of like amp whine. Any more ideas? Is it a problem?

 

I have close to 10,000 miles and the whinning noise is getting worse!!!!! Mine sounds a little like a volkswagen bug. When i "blip" the gas I hear a little whine. The whine is even more prenounced as you accelerate. You can hear it in all gears but most noticable in ist and second gears. I took it to the dealer and he told me Nissan is aware that people are complaning, but they aren't saying what the problem is. I am going to call Nissan and ask tomorrow.

 

yeah i brought my car to the dealer to get the windows tinted and I mentioned to the guy about the whine, he said he'll have a tech drive it to see if there was a problem, they told me it was normal noise and it happens on all Z's and all rear wheel drive cars. This guy though i was a fool, he tried telling me its the tires. I insisted it wasn't and I know this noise is not normal. If it wasn't a lease i would make a big deal about it but, instead i'll continue to beat the **** out of it and bring it back if something goes wrong. I got to get my $$$ worth.

BTW I have 2200 miles and the noise is still there... SO FREAKIN ANNOYING...I'm thinkin of removing the resonator and putting on a flowmaster to make the car louder so I don't have to hear this noise anymore.