That response was in reply to the post by DeeZflip who was specifically referring to the "cold air intake" problem so not sure why that would make any connection from that. You also mention the description "whistle" 3 times which we aren't claiming and I make specific mention of.

Your transmission is bad. Ours are not having the same symptoms you are referencing such as balking shifting or grinding of gears. We can't say for certain it isn't possible but in my opinion it's not "most likely" the transmission as you mentioned in an earlier post. Right now I can't say there is any "most likely" since apparently no one has a documented cause and fix for this exact issue. Unless I've misunderstood and you are saying that.

Opinions relating to the specific problem are most certainly welcome.


EDIT: We'll be most interested in hearing the outcome of the new transmission.

 

I don't see what the point of arguing who's right or who's wrong is. We don't know what the problem is. You are right, maybe i shouldn't have used the words "most likely" since we are unsure. But these are the same symptoms that I have (this is the op's first post), and my problem is the transmission. It's my .02

* It sounds like a wind leak through the window, but it's still there when i roll the window down.
* i can be in gear or in neutral, accelerating, coasting, or braking.
* i'm having a hard time telling where its coming from, other than the front of the car and i THINK the front driver side.
* once i've been driving for a few minutes it goes away, so obviously whatever it is must be at least a little temp-related.
* no vibration or irregular feeling accompanies the sound

Let's move on.

 

Ok...try this. Right before you get ready in the morning. Start your car, let it warm up while you get ready for work, sit on the toilet, shave, eat breakfast, shower, or whatever. That should let the car warm up a good amount of time(if you don't care too much for waisting a little bit of gas). Oh! and get your cabin nice and toasty and let the heat run. Heating up the cabin on the G takes a good amount of time compared to my girlfriend's honda.

For less chances of someone jacking your car, you can lock the car with the engine running with the keyfob, just bring the keyfob with you and press the lock button, you should hear the door lock.

You shouldn't hear the howling/whine when doing this. This makes me think that it's not transmission related but who knows. Maybe something with the air outside being restricted until the heating coil warms up...who knows either.

What I've wanted to try is to warm the car the same amount of time but without heating the cabin up and see if it still makes that noise. Having the heating system completely on OFF.

 

Me too...usually the engine AND my cabin is warmed up by then.

 

I'm not arguing who is right or wrong. Right now no one has a verified answer.

My only purpose is to ensure we are discussing the facts of the same issue as we work together exploring plausible theories for the solution. I've been on way too many threads with misinformation and unrelated problems.

In any case I'm happy to move along.

My symptoms mirror yours although I would describe the sound as a combination of a howl, roar and whine if that makes any sense. It does seem similar to the sound of wind from an open window although is more sensitive to speed and perhaps a little lower pitch. I have also noted that the pitch appears to change a bit with a bump in the road while driving at the same speed.

My dealer has taken off the wind deflector on the front of the muffler to see if that helped but it didn't. They also removed the heat shield on another occasion to see if that helped but no success. We also carefully examined all of the aero affects that come standard with the 6MT cars (at least here in Canada).

Can you clarify that you are or aren't experiencing problems such as grinding with your transmission? I can't seem to see that anyone with an AT has had the problem.

 

Hey, for what its worth I have had the same exact noise when its cold outside. Ive had it since the car was new. 30k miles on the car now - the transmission is fine. Actually I have not had 1 problem with the car.

 

^other than a whine while cold

 

Same issue here - 06 coupe mt 31k
I hear it in the cold until the car heats up. Gear doesn't seem to matter.
Subscribed..

 

I have the same noise... 70k and it shifts great.

 

^try opening your window to see if it goes away. If you're like me there is no difference in pitch or volume.

 

bumping this. Was doing more research and found a 4 page thread on a Z forum of 350Zs with the same issue. Seems they all keep throwing transmission parts at the issue and then report back that it's not fixed. It's getting more and more clear to me that a widespread general problem exists that isn't tranny related, and people just keep replacing throwput bearings because they don't have any new ideas.

We've got a huge community here; this is something we can get together and deal with without a dealer. Next time it's warm n dry I'll be getting under the hood and poking around at the compressor. If that doesn't work I'll try something else till I find it.

Anyone else got anything new?

 

.
That's the thing though...you might not hear it when it's warm n dry. You have to get up in there when it's freezing cold.

 

yeah i know. although if i can find something that looks like it might be causing it, that's still better than where we're at now. until we can find a flap of some sort that's actuated based on engine heat, it doesn't matter whether we can fix it or not, the whole thing is just conjecture.

 

found another G owner online and started emailing with him. he's currently thinking it's his rear diff, and has some interesting points. copying his email for the added input:

"As background - I have a 2004 G35 sedan with a manual transmission.

1. The sound is present long after the engine temp has come up to normal. In fact, I could idle the car for 20 minutes and if its a cold day and the car has been sitting, the sound still occurs once I get going.

2. If I've drivien the car recently, but there has been enough time for the engine to cool, the sound will not occur once you drive again. It seems to only occur after sitting for a long period of time in the cold.

3. Only occurring in Manual Transmissions. This would indicate its occurring someplace that is different than the components on an automatic. Unless this flap is in fact different on Manual's.

4. As well, if I drive very slowing after it sits for awhile, like after work in rush hour traffic, the sound won't start up until I get up a decent speed, even after the engine is warm. Support your theory on speed related, because I also experience it in all gears, although the range of speed is a little wider than what you have.

For these reasons, I think there's merit to the idea its in the Rear Diff. The rear diff and the viscous coupling housed within - I'm told its a different component that on the Auto trannys. Given that part spins at the speed of travel and doesn't alter with your gear changes, it would still fit the theory. I got to believe that the fluid inside takes much longer to warm up that the engine does, and would only warm up if the car was moving - which is consistent with what I'm experiencing. Finally, I discovered that the sound was worse after I got my last major service, and after some poking around, discovered that they changed the diff fluid in that service call, and used a slightly different type. I think there may be something to the theory that the component makes this sound until the fluid loosens up and is flowing properly.

I'm going in for a service call later this month and am going to leave the car there overnight and then ride with them in the morning after the hook up their mechanics stethoscope to the rear diff and see if the sound is originating from there. If that's the issue, I'm hoping a different type of synthetic fluid will help.

Or, this could be all a big waste of time. Its been a long 5 years of winter.

Does any of this make sense? "

i'll follow up here as well once i hear back from him on what he found out at the service.

also, [strikethrough]has anyone with the VLSD had this problem?[/strikethrough] (EDIT: still new to this car n figuring out whether or not we have a VLSD. apparently i do? its like christmas!) or an upgraded diff at all? if not, that adds more credence to his thoughts, and also gives a decent motivation to upgrade read diffs.

 

^Thanks for the update. Those are some interesting observations.

I'm not so sure about the differential theory since all 6mt cars have a limited slip axle as standard equipment and it also is included in the AT coupes with the performance package (18" wheels). That package may not be the same in US cars however. Perhaps there are also AT cars with the limited slip experiencing this however.

EDIT: I have changed my diff fluid three times and with different synthetic products each time.