2006 350z i have a humming noise that humms then fades away, at normal speeds. Has anyone ran into this problem. It last for 4 seconds and fads away for another 4 seconds..no mater what my speed is its always the same. does not get faster or slower.

 

Do you have an aftermarket audio system?

 

No my car is all stock..

 

could be a number of things, drive-shaft, tranny whine, tires, differential.............

 

It never does it when stopped?

Probably a wheel bearing. How many km/what year is your Z. It could help to gage that. The wheel bearing will humm randomly when it first starts failing, it will continue to do this for some time until it becomes a constant droning humm. A good way to check is jack the car up (suspect wheel or all 4) and spin it, if it spins freely and smoothly with no vibrations chances are it is not a problem. If it spins freely but sounds/feels like there is sand in your wheel bearing then you have likely found the problem, or a new one .

 

Parker, Thanks for the info..will look into this, this weekend.

 

Old Park', I thank you, too, just in case it ever happens to me. BTW, do you recommend replacing just the faulty wheel bearing or all four--like just to "get it outta the way"?!

 

If you have deep pockets

But no I don't, the loads and elements that each wheel bearing are subjected to are different for each wheel depending on where you drive and your driving habbits.

Wheel bearings don't catastrophically fail, you can hear them failing and you will continue to notice the condition of the wheel bearing worsen for 100's or even 1000 miles before it actual failes and seizes. Although I don't recommend testing how far you can make it on a failing wheel bearing lol. You will have lots of notice and time to replace the other wheel bearings once they begin to go as well.

 

Hey parker, I did all the wheel bearings this weekend, but it is very hard to tell which bearing is causing the noise without load on the wheels. And yes my 350z has 65,500 highway miles.