NOISE FROM THE REAR -3.0i E89

[Maria1]

Our E89 makes a rhythmic woo woo woo noise from the rear of the car and the frequency of the "woo wooing" increases with speed so its definitely speed related which indicates its something to do with something turning/spinning. It has been like this for 5000 miles.

Many have said it's a tyre flat spot. Thats why I left it. unfortunately this is now ruled out as the tyres have just been replaced all round. It could be a wheel bearing but the MoT found nothing wrong with the bearings. There is nothing obviously wrong with the drive shafts or differential. the car is an auto with 24,000 miles. It could be some brake binding but this would be evident with extra due around the wheel and obvious bidding when spinning the wheel. This does not happen and the MoT test said the brakes were really good.

I am stumped. Any views please before I do another 1200 miles in two weeks?

[mkinternet]

Could be the diff or the centre carrier bearing on the driveshaft - how many miles has the car done and is it a manual or auto???

!!!! Sorry you mention the mileage and gearbox - should have read your post more carefully

[rdm05z4]

Are you sure the noise is not from your passenger with arm out the window. Going Woo Woo Woo as you speed up? Sorry could not resist can't offer advice on your issue but good luck.

[B21]

Does the sound change with de acceleration or acceleration?

[MikeyH]

Does it get louder when you go round corners and if so is it worse going left or right?

[MikeyH]

Could it be that a wheel is not straight causing some kind of resonance with wind through the spokes?

[ml1nov1980]

2011 z4 30I automatic 105k. I have something similar. My Z makes a humming sound from the rear and will change in intensity with the rpm?? Changed the rear differential fluid , no change? If I have the radio on or top down it seems to work fine ☺☺☺☺

[javis20]

I just went thru all of this with my 2011 Z4 E89 70k miles. Turned out to be a bent wheel. In my case a substantially bent rear right wheel. Two other wheels are slightly bent. You would think they would find it when installing new tires? Yea right.. BMW dealer installed new tires and did alignment on bent wheels. In my case the differential was also making noise. But the wo wo noise was the wheels. Bought a new right rear wheel and the noise was gone. It was a local indie who diagnosed the real problem.

[ml1nov1980]

Did you ever do anything with the differential to eliminate that noise? Or just drive it as is? I just got mine back from the shop this afternoon and the mechanic confirmed it is the differential! He could hear it while driving, But when he raised the car on a hoist it would not do it, he could only slightly hear it with a stethoscope! So that tells me the noise only happens when you accelerate and the differential is under a load, the noise stops as soon as you de-accelerate (let up on the gas pedal) likely pinion bearings!
Mechanic suggested I just turn the radio up and drive it, it could last year's or it could go tomorrow!! A new differential assembly is about $2400 and another $850 for install ouch!
I can pick up a salvage for about $500 and still $850 for install. Don't know what to do??? I'm sure whatever I choose will be the wrong one

[javis20]

I found a replacement differential for $530 on ebay, with only 39K miles. Local indy shop installed for less than $500. That took care of some of the noise. The wo wo noise was the bent wheel. Take the wheel to a tire shop and have them double check it on their balancer. Even the dealer didn't check the wheel when I complained about the noise.

I use salvage yards via Ebay. If there is anything wrong you will get your money back. Ebay always sides with the buyer. Usually the salvage yard will give the vin of the donor car. You can then search the vin and confirm how the car was damaged and mileage.