I have a noise comming from the back of my z (a kind of whirring noise) starts at around 40 kph and the sound is constant with the road speed (not the engine speed) its just as loud whether accelerating or breaking but sometimes it quietens down when cornering its not the pads ive had them done its not the tyres ive had them changed too any ideas???? its getting quite embarasing when it looks great but sounds like a nail from the inside.

Could be a bearing or the Diff.

sounds like wheel bearing, if it goes turning left its the right bearing and vice a versa or was it the otherway around? sorry its been a while since i changed any. also w/bearing is cheeper than diff, hope this solves your problems (CHEEPLY)

Is there any vibration at all???

 

If there is it could be a worn gearbox mounting..

 

 

it does seem like its vibrating a bit now aswell and also i swear its getting louder but it might be just me.

Have you considered the fuel pump ?

nope but it feels too road speed related to be something like that.

Check simple stuff 1st - it may be something rubbing the wheel like wheel arch lining. Otherwise, is diff oil level Ok? Could be wheel bearing or brakes rubbing. Could be drive shaft mounting.

 

Raise the back of the car & start the engine in gear, get the rear wheels spinning and listen for the noise. Make sure car is properly supported and take all safety precautions!! If the rear wheels touch the ground you in big doodoo!

I'm a bit reluctant to do that knowing my luck ill be looking underneath it and the car will shake itself loose and go bollocking off down the road on its own!

Does that noise tend to dissappear after the car warms up?

 

is it a sort of whining noise?

Its sort of a whirring noise that seems to get worse as it warms up it also it tends to get a bit quieter in left hand bends (but even then its still loud) and louder on right hand bends but not loads louder as its already bloody loud! I dont know if this is a clue but it makes the rear passenger side trim vibrate too. and its louder in the car than it is out of the car. i'm stumped.any ideas greatly appreciated.

Easiest possibility is the rear pad wear indicators hitting the disc to tell you they're worn out - check ALL FOUR rear brake pads first

 

CheerZ,

 

Andy

Had the pads done by jeff tt a week or so ago no chane in the noise.