Hello all,
I recently noticed a "humming" or whine" coming from our 2004 350ZX. It became noticeable on the highway about 5 minutes after we began driving. On the way home after having diner, I again noticed the noise after about 5 minutes.
The best way I can describe it would be tire hum or meshing gears. The noise seems to vary directly with car speed. It seems to be coming from the back end of the car.

Any ideas where to start tracking this down would be greatly appreciated.

Regards,
Jeff

 

Could be wheel bearings, could be low differential fluid, could be something stuck back there that's rubbing on something rotational.. Did this start happening spontaneously? What troubleshooting have you done?..

 

For me it was a spontaneous occurrence. I haven't ridden in the car for a few weeks (girlfriend's car). it wasn't there the last time I was in the car.

Have not done any trouble shooting yet. Just heard it recently. I was hoping to get some ideas where to start looking. I will be able to get a look under the car tomorrow. My first thoughts were something with the differential or the tires. I figured that would be the first place to look. I also wanted to get some input from those who have experience with these cars. I did not think of the wheel bearings....

 

The car makes a very noticeable humming, and whiny sounds especially when your off the throttle, its probably just a normal sound you never really noticed...

It becomes much more pronounced once you upgrade the subframe and differential bushings.

 

I really think this is a new sound. It's loud enough I would have noticed this before.